Chapter 2. Installing and Upgrading MySQL
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## Chapter 2. Installing and Upgrading MySQL

## 2.1. MySQL Installation Overview

This chapter describes how to obtain and install MySQL. You can choose to install MySQL Enterprise or MySQL Community Server:

- MySQL Enterprise is MySQL AB's commercial offering for modern enterprise businesses. It includes MySQL Enterprise Server and the services provided by MySQL Network. To install MySQL Enterprise, see Section 2.3, “Installing MySQL Enterprise”.

- MySQL Community Server is for users who are comfortable configuring and administering MySQL by themselves. To install MySQL Community Server, see Section 2.4, “Installing MySQL Community Server”.

If you plan to upgrade an existing version of MySQL to a newer version rather than install MySQL for the first time, see Section 2.4.16, “Upgrading MySQL”, for information about upgrade procedures and about issues that you should consider before upgrading.

If you are interested in migrating to MySQL from another database system, you may wish to read Section A.9, “MySQL 5.0 FAQ — Migration”, which contains answers to some common questions concerning migration issues.

## 2.2. Determining your current MySQL version

To determine the version and release of your currently installed MySQL installation, there are a number of options.

- Using a command client (`mysql`), the server version of the MySQL server that you are connected to will be shown once you are connected. The server version information will include `community` or `enterprise` accordingly.

  For example, here is the output from a MySQL Community Server edition installed on Linux:

      Welcome to the MySQL monitor.  Commands end with ; or \g.
      Your MySQL connection id is 6
      Server version: 5.0.27-standard MySQL Community Edition - Standard (GPL)

      Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

      mysql>

  Below is the output from MySQL Enterprise Server on Windows:

      Welcome to the MySQL monitor.  Commands end with ; or \g.
      Your MySQL connection id is 2
      Server version: 5.0.28-enterprise-gpl-nt MySQL Enterprise Server (GPL)

      Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

      mysql>

- You may also determine the version information using the version variables. Both the version and version_comment variables contain version information for the server you are connected to. Use the `SHOW VARIABLES` statement to obtain the information you want. For example:

      mysql> show variables like "%version%";
      +-------------------------+------------------------------------------+
      | Variable_name           | Value                                    |
      +-------------------------+------------------------------------------+
      | protocol_version        | 10                                       |
      | version                 | 5.0.27-standard                          |
      | version_comment         | MySQL Community Edition - Standard (GPL) |
      | version_compile_machine | i686                                     |
      | version_compile_os      | pc-linux-gnu                             |
      +-------------------------+------------------------------------------+
      5 rows in set (0.04 sec)

      mysql>

- The `STATUS` command will display the version and version comment information. For example:

      mysql> status;
      --------------
      ./client/mysql  Ver 14.12 Distrib 5.0.29, for pc-linux-gnu (i686) using readline 5.0

      Connection id:          8
      Current database:
      Current user:           mc@localhost
      SSL:                    Not in use
      Current pager:          /usr/bin/less
      Using outfile:          ''
      Using delimiter:        ;
      Server version:         5.0.27-standard MySQL Community Edition - Standard (GPL)
      Protocol version:       10
      Connection:             Localhost via UNIX socket
      Server characterset:    latin1
      Db     characterset:    latin1
      Client characterset:    latin1
      Conn.  characterset:    latin1
      UNIX socket:            /tmp/mysql.sock
      Uptime:                 1 day 3 hours 58 min 43 sec

      Threads: 2  Questions: 17  Slow queries: 0  Opens: 11  Flush tables: 1  Open tables: 6  Queries per second avg: 0.000
      --------------

- MySQL Administrator will show the server version within the Server Information tab. Only the value of the `version` information is shown.

## 2.3. Installing MySQL Enterprise

This section does not apply to MySQL Community Server users.

This section contains information about the components, installation and initial configuration requirements for installing MySQL Enterprise.

### 2.3.1. Overview of MySQL Enterprise Installation

This section does not apply to MySQL Community Server users.

To obtain MySQL Enterprise, visit http://www.mysql.com/products/enterprise/. The platforms that are officially supported for MySQL Enterprise are listed at http://www.mysql.com/support/supportedplatforms.html.

To install MySQL Enterprise, install the main distribution plus the latest available service pack or hot-fix. You only need to install the latest service pack or hot-fix – this will include all updates since the previous main distribution release Enterprise Installer. For platforms that do not yet have an Enterprise Installer, use the Community Server instructions (see Section 2.4, “Installing MySQL Community Server”).

### 2.3.2. Enterprise Server Distribution Types

This section does not apply to MySQL Community Server users.

Enterprise Server releases will be created for the following packages from the MySQL 5.0 tree:

- `mysql-enterprise`: Released under a commercial license and includes the following storage engines: `MyISAM`, `MEMORY`, `MERGE`, `InnoDB`, `ARCHIVE`, `BLACKHOLE`, `EXAMPLE`, `FEDERATED`.

- `mysql-enterprise-gpl`: Same as `mysql-enterprise`, but released under the GPL.

- `mysql-cluster`: `mysql-enterprise` plus MySQL Cluster (`NDB`).

- `mysql-classic`: Released under a commercial license, does not include `InnoDB`.

- `mysql-community`: Same as `mysql-enterprise-gpl`, but available for the community, and released every 6 months.

Some packages include additional servers that are built with debugging support but are otherwise configured identically to the non-debug servers. Eventually, all packages will include them.

To satisfy different user requirements, we provide several servers. mysqld is an optimized server that is a smaller, faster binary. mysqld-debug is compiled with debugging support.

Each of these servers is compiled from the same source distribution, though with different configuration options. All native MySQL clients can connect to servers from either MySQL version.

### 2.3.3. MySQL Enterprise Contents

This section does not apply to MySQL Community Server users.

MySQL Enterprise consists of the MySQL Enterprise Server and MySQL Network, which contains the Monitoring and Advisory Service, access to the Knowledge Base, and more. The MySQL Enterprise Installer provides a single installation package that can install MySQL Enterprise, and a number of additional components including the MySQL Connectors and MySQL Documentation in a number of different formats.

The full list of components provided by the MySQL Enterprise Installer is as follows:

- MySQL Enterprise Server, incorporating:

  - MySQL Database Server (`mysqld`)

  - MySQL command-line tools and utilities

  - Developer components (including the MySQL Client Library for use with third party tools and connectors; and the API for C/C++ developers)

- MySQL Network Service Agent

- MySQL GUI Tools, incorporating:

  - MySQL Administrator

  - MySQL Query Browser

  - MySQL Workbench

  - MySQL Migration Toolkit (Windows only)

- MySQL Connectors, including:

  - MySQL Connector/J — a JDBC compliant Java interface

  - MySQL Connector/ODBC — an ODBC driver

  - MySQL Connector/NET — an ADO.NET compatible driver for the .NET environment and languages

- MySQL Documentation, incorporating the documentation for the server, command line tools and connectors.

Enterprise Installers are currently available for the following platforms:

- Windows x86 (including Windows 2000, Windows XP and Windows Server 2003)

- SuSE Linux x86 and X64

- RedHat Enterprise Linux 4 x86 and X64

### 2.3.4. Running the Enterprise Installer

This section does not apply to MySQL Community Server users.

MySQL Enterprise includes an installer for supported platforms that will guide you through the installation process for all the components of MySQL Enterprise.

#### 2.3.4.1. Using the Enterprise Installer for Windows

The Enterprise Installer for Windows provides both background information on MySQL and links to the MySQL Web site and documentation. The installer can be used to add any of the MySQL Enterprise components to your Microsoft Windows 2000, Windows XP or Windows Server 2003 computers.

To start the installation process:

Double click on the `mysql-enterprise-`VERSION`-win32.exe` installer application, where `VERSION` is the version number of the release you are installing. For example, `mysql-enterprise-5.0.26-win32.exe`. There may be a slight pause before the installer shows the first stage of the installation process as the installer extracts some components.

#### 2.3.4.2. Using the Enterprise Installer for Linux

This section does not apply to MySQL Community Server users.

The Enterprise Installer for Linux is available for a number of different platforms. The installer is an executable component that provides a GUI interface (using the X Windows System) to the installation process using the native package management format (for example RPM). Alternatively, you may install the RPMs individually from the command line.

To use the Linux Enterprise Installer:

- You must be logged in as root (superuser). If you are not logged in as root, you will be able to run the installer, but the installation process will fail.

- You must have access to a system running the X Window System (X11). The system on which you are running the installer, and the system where the installer interface is executing do not need to be the same. The installer is self-contained; the window manager and libraries that are installed on your system should not affect your ability to run the installer. For details on remote installation, see below.

- The installer must be executed on the system on which you want to install MySQL Enterprise.

To start the installer, extract the installation package:

    shell> bunzip2
        mysql-enterprise-VERSION.PLATFORM.x86_64.tar.bz
    shell> tar xf mysql-enterprise-VERSION.PLATFORM.x86_64.tar

`VERSION` is the version number of the MySQL Enterprise release that you are installing; `PLATFORM` is the name of the supported platform, for example `rhel4` for RedHat Enterprise Linux v4.

The installer and packages can be located in the sub directory created when the files were extracted. You should change to this directory and then run the

    shell> cd mysql-enterprise-VERSION
    shell> ./installer

To the run the installer on the target machine, with the installer display being provided on a different on a different X11 server, set the `DISPLAY` environment variable:

    shell> DISPLAY=remote:0.0 ./installer

You should replace the `remote:0.0` with the hostname and display/screen number for the display you are using.

Once started, you will be presented with the main installer window, as shown below. Note that the format of this window may differ depending on the window manager (KDE, Gnome, etc.) that you might have installed.

To install from directly from the RPMs without using the installer, change to the `packages` directory within the main MySQL Enterprise installer directory and type:

    shell> rpm -iv mysql-*.rpm

If you upgrading from a previous version of any of these packages, use:

    shell> rpm -Uv mysql-*.rpm

#### 2.3.4.3. Choosing What to Install

This section does not apply to MySQL Community Server users.

Whether you are running the Enterprise Installer under Windows or Linux, the basic interface and options available to you are the same. Initially, you will be offered three choices:

- Preparation — this section of the installer enables you to examine the hardware and software requirements of MySQL Enterprise before you start the installation process. Please read this information carefully.

  Release notes provide information on the changes, bug fixes, and issues within the corresponding release. Please note that release notes in this section of the installer are currently provided only for the MySQL server component. You should read this information carefully, as the notes provided will list the bug fixes and major functionality changes that affect this release. You should ensure that these will not affect your existing installation before continuing the installation process. For information on all releases, different release types, and schedules, please see Appendix E, MySQL Enterprise Release Notes.

  For information on the changes in MySQL Network Monitoring and Advisory Service, the MySQL GUI Tools and Connectors, please see the relevant section of Appendix G, MySQL Change History.

- Installation — this is the main installation process and interface. A number of options are provided so that you can run choose which components to be installed. For more information, see Section 2.3.4.3.1, “MySQL Enterprise Installation Process”.

- Other Information — this sections provides links for the MySQL web site and the MySQL Enterprise License Agreement.

If you exit the installer at this stage, using the Exit link, no software will have been installed.

##### 2.3.4.3.1. MySQL Enterprise Installation Process

To install MySQL components, choose option 2 (Installation). The main installation screen enables you to select the type of installation.

Four different installation options are available:

1. Server Default — this installs all of the components required for running a MySQL database server, including the core server application, command line utilities, the MySQL client library, and documentation. The MySQL GUI tools and connectors are not installed with this option.

2. Client Default — this installs all of the components required for a client to communicate with a MySQL database server. This includes the MySQL client library, GUI tools, connectors, and documentation.

3. Full — this installs all the available components, including MySQL database server, client library, GUI tools, connectors, and documentation.

4. Custom — this option enables you to select the individual components to be installed. You can choose not only the major groups (for example MySQL database server) but also individual subcomponents (command-line utilities). You will need to select the individual components that you want to install.

These options are summarized in the table below.

Component | Server Default | Client Default | Full | Custom
MySQL Server | Yes | No | Yes | Optional
Client Library | Yes | Yes | Yes | Optional
GUI Tools | No | Yes | Yes | Optional
Connectors | No | Yes | Yes | Optional
Documentation | Yes | Yes | Yes | Optional

### MySQL Network Service Agent

The MySQL Network Service Agent can be installed by selecting the appropriate option when the installation process for the main components has been completed.

You must have a MySQL Network Monitoring and Advisory Service Network Manager already installed and running on your network to use the Service Agent. You will need the MySQL Agent URL to complete the configuration process.

Once you have selected the type of installation, or selected the individual components to be installed if you have selected the Custom installation type, the installation process will start to copy the files, applications and other components to your machine.

The installation process will take some time, with the exact period depending on the features and options that you have selected to install.

Once the process has completed, you will need to click Next to complete the post-installation process. You can choose to automatically execute the MySQL Server Configuration Wizard (which provides an interface for configuring the parameters of your MySQL Server installation) and the MySQL Network Monitoring and Advisory Service Installer.

To complete the installation sequence and execute the optional post-installation processes, click Finish.

### 2.3.5. Post-Install Procedures

This section does not apply to MySQL Community Server users.

After installation, depending on the options you selected on the final screen, you may be asked to complete the MySQL Server Configuration Wizard and/or the MySQL Network Service Agent installer.

### 2.3.6. MySQL Server Configuration Wizard

The MySQL Server Configuration Wizard helps automate the process of configuring your server. It creates a custom MySQL configuration file (`my.ini` or `my.cnf`) by asking you a series of questions and then applying your responses to a template to generate the configuration file that is tuned to your installation.

The MySQL Server Configuration Wizard is included with the MySQL 5.0 server. For Community Server users, the MySQL Server Configuration Wizard is available only for Windows. For Enterprise Server users, the MySQL Server Configuration Wizard is included as part of the standard Enterprise Installer.

The MySQL Server Configuration Wizard is to a large extent the result of feedback that MySQL AB has received from many users over a period of several years. However, if you find that it lacks some feature important to you, please report it in our bugs database using the instructions given in Section 1.8, “How to Report Bugs or Problems”.

#### 2.3.6.1. Starting the MySQL Server Configuration Wizard

The MySQL Server Configuration Wizard is normally started as part of the installation process. You should only need to run the MySQL Server Configuration Wizard again when you need to change the configuration parameters of your server.

##### 2.3.6.1.1. The MySQL Server Configuration Wizard on Windows

You can launch the MySQL Configuration Wizard by clicking the MySQL Server Instance Config Wizard entry in the MySQL section of the Windows Start menu.

Alternatively, you can navigate to the `bin` directory of your MySQL installation and launch the `MySQLInstanceConfig.exe` file directly.

The MySQL Server Configuration Wizard places the `my.ini` file in the installation directory for the MySQL server. This helps associate configuration files with particular server instances.

To ensure that the MySQL server knows where to look for the `my.ini` file, an argument similar to this is passed to the MySQL server as part of the service installation:

    --defaults-file="C:\Program Files\MySQL\MySQL Server 5.0\my.ini"

Here, `C:\Program Files\MySQL\MySQL Server 5.0` is replaced with the installation path to the MySQL Server. The `--defaults-file` option instructs the MySQL server to read the specified file for configuration options when it starts.

Apart from making changes to the `my.ini` file by running the MySQL Server Configuration Wizard again, you can modify it by opening it with a text editor and making any necessary changes. You can also modify the server configuration with the MySQL Administrator utility. For more information about server configuration, see Section 5.2.2, “Command Options”.

MySQL clients and utilities such as the mysql and mysqldump command-line clients are not able to locate the `my.ini` file located in the server installation directory. To configure the client and utility applications, create a new `my.ini` file in the Windows installation directory (for example, `C:\WINDOWS` or `C:\WINNT`).

Under Windows Server 2003, Windows Server 2000 and Windows XP, MySQL Server Configuration Wizard will configure MySQL to work as a Windows service. To start and stop MySQL you use the `Services` application that is supplied as part of the Windows Administrator Tools.

##### 2.3.6.1.2. Starting the MySQL Server Configuration Wizard on Linux

This section does not apply to MySQL Community Server users.

To start the MySQL Configuration Wizard on Linux, you must run the `mysqlsetup` command. You must be running an X Windows System server for the MySQL Server Configuration Wizard.

To display the MySQL Server Configuration Wizard interface on a different machine, set the value of the `DISPLAY` variable on the command line:

    shell>
    DISPLAY=remote:0.0 mysqlsetup

The MySQL Server Configuration Wizard places the `my.cnf` file in the `/etc` directory.

This configuration file is automatically used when `mysqld` is started. The standard MySQL server initialization script, typically located within `/etc/init.d/mysql`, will also use this file automatically.

Apart from making changes to the `my.ini` file by running the MySQL Server Configuration Wizard again, you can modify it by opening it with a text editor and making any necessary changes. You can also modify the server configuration with the MySQL Administrator utility. For more information about server configuration, see Section 5.2.2, “Command Options”.

#### 2.3.6.2. Choosing a Maintenance Option

If the MySQL Server Configuration Wizard detects an existing configuration file, you have the option of either reconfiguring your existing server, or removing the server instance by deleting the configuration file and stopping and removing the MySQL service.

To reconfigure an existing server, choose the Re-configure Instance option and click the Next button. Any existing configuration file is not overwritten, but renamed (within the same directory) using a timestamp (Windows) or sequential number (Linux). To remove the existing server instance, choose the Remove Instance option and click the Next button.

If you choose the Remove Instance option, you advance to a confirmation window. Click the Execute button. The MySQL Server Configuration Wizard stops and removes the MySQL service, and then deletes the configuration file. The server installation and its `data` folder are not removed.

If you choose the Re-configure Instance option, you advance to the Configuration Type dialog where you can choose the type of installation that you wish to configure.

#### 2.3.6.3. Choosing a Configuration Type

When you start the MySQL Server Configuration Wizard for a new MySQL installation, or choose the Re-configure Instance option for an existing installation, you advance to the Configuration Type dialog.

There are two configuration types available: Detailed Configuration and Standard Configuration. The Standard Configuration option is intended for new users who want to get started with MySQL quickly without having to make many decisions about server configuration. The Detailed Configuration option is intended for advanced users who want more fine-grained control over server configuration.

If you are new to MySQL and need a server configured as a single-user developer machine, the Standard Configuration should suit your needs. Choosing the Standard Configuration option causes the MySQL Configuration Wizard to set all configuration options automatically with the exception of Service Options and Security Options.

The Standard Configuration sets options that may be incompatible with systems where there are existing MySQL installations. If you have an existing MySQL installation on your system in addition to the installation you wish to configure, the Detailed Configuration option is recommended.

To complete the Standard Configuration, please refer to the sections on Service Options and Security Options in Section 2.3.6.10, “The Service Options Dialog”, and Section 2.3.6.11, “The Security Options Dialog”, respectively.

#### 2.3.6.4. The Server Type Dialog

There are three different server types available to choose from. The server type that you choose affects the decisions that the MySQL Server Configuration Wizard makes with regard to memory, disk, and processor usage.

- Developer Machine: Choose this option for a typical desktop workstation where MySQL is intended only for personal use. It is assumed that many other desktop applications are running. The MySQL server is configured to use minimal system resources.

- Server Machine: Choose this option for a server machine where the MySQL server is running alongside other server applications such as FTP, email, and Web servers. The MySQL server is configured to use a moderate portion of the system resources.

- Dedicated MySQL Server Machine: Choose this option for a server machine that is intended to run only the MySQL server. It is assumed that no other applications are running. The MySQL server is configured to use all available system resources.

#### 2.3.6.5. The Database Usage Dialog

The Database Usage dialog allows you to indicate the storage engines that you expect to use when creating MySQL tables. The option you choose determines whether the `InnoDB` storage engine is available and what percentage of the server resources are available to `InnoDB`.

- Multifunctional Database: This option enables both the `InnoDB` and `MyISAM` storage engines and divides resources evenly between the two. This option is recommended for users who use both storage engines on a regular basis.

- Transactional Database Only: This option enables both the `InnoDB` and `MyISAM` storage engines, but dedicates most server resources to the `InnoDB` storage engine. This option is recommended for users who use `InnoDB` almost exclusively and make only minimal use of `MyISAM`.

- Non-Transactional Database Only: This option disables the `InnoDB` storage engine completely and dedicates all server resources to the `MyISAM` storage engine. This option is recommended for users who do not use `InnoDB`.

#### 2.3.6.6. The InnoDB Tablespace Dialog

Some users may want to locate the `InnoDB` tablespace files in a different location than the MySQL server data directory. Placing the tablespace files in a separate location can be desirable if your system has a higher capacity or higher performance storage device available, such as a RAID storage system.

To change the default location for the `InnoDB` tablespace files, choose a new drive from the drop-down list of drive letters and choose a new path from the drop-down list of paths. To create a custom path, click the ... button.

If you are modifying the configuration of an existing server, you must click the Modify button before you change the path. In this situation you must move the existing tablespace files to the new location manually before starting the server.

#### 2.3.6.7. The Concurrent Connections Dialog

To prevent the server from running out of resources, it is important to limit the number of concurrent connections to the MySQL server that can be established. The Concurrent Connections dialog allows you to choose the expected usage of your server, and sets the limit for concurrent connections accordingly. It is also possible to set the concurrent connection limit manually.

- Decision Support (DSS)/OLAP: Choose this option if your server does not require a large number of concurrent connections. The maximum number of connections is set at 100, with an average of 20 concurrent connections assumed.

- Online Transaction Processing (OLTP): Choose this option if your server requires a large number of concurrent connections. The maximum number of connections is set at 500.

- Manual Setting: Choose this option to set the maximum number of concurrent connections to the server manually. Choose the number of concurrent connections from the drop-down box provided, or enter the maximum number of connections into the drop-down box if the number you desire is not listed.

#### 2.3.6.8. The Networking and Strict Mode Options Dialog

Use the Networking Options dialog to enable or disable TCP/IP networking and to configure the port number that is used to connect to the MySQL server.

TCP/IP networking is enabled by default. To disable TCP/IP networking, uncheck the box next to the Enable TCP/IP Networking option.

Port 3306 is used by default. To change the port used to access MySQL, choose a new port number from the drop-down box or type a new port number directly into the drop-down box. If the port number you choose is in use, you are prompted to confirm your choice of port number.

Set the Server SQL Mode to either enable or disable strict mode. Enabling strict mode (default) makes MySQL behave more like other database management systems. If you run applications that rely on MySQL's old “forgiving” behavior, make sure to either adapt those applications or to disable strict mode. For more information about strict mode, see Section 5.2.6, “SQL Modes”.

#### 2.3.6.9. The Character Set Dialog

The MySQL server supports multiple character sets and it is possible to set a default server character set that is applied to all tables, columns, and databases unless overridden. Use the Character Set dialog to change the default character set of the MySQL server.

- Standard Character Set: Choose this option if you want to use `latin1` as the default server character set. `latin1` is used for English and many Western European languages.

- Best Support For Multilingualism: Choose this option if you want to use `utf8` as the default server character set. This is a Unicode character set that can store characters from many different languages.

- Manual Selected Default Character Set / Collation: Choose this option if you want to pick the server's default character set manually. Choose the desired character set from the provided drop-down list.

#### 2.3.6.10. The Service Options Dialog

This section does not apply to MySQL Community Server users.

On Windows NT-based platforms, the MySQL server can be installed as a Windows service. When installed this way, the MySQL server can be started automatically during system startup, and even restarted automatically by Windows in the event of a service failure.

The MySQL Server Configuration Wizard installs the MySQL server as a service by default, using the service name `MySQL`. If you do not wish to install the service, uncheck the box next to the Install As Windows Service option. You can change the service name by picking a new service name from the drop-down box provided or by entering a new service name into the drop-down box.

To install the MySQL server as a service but not have it started automatically at startup, uncheck the box next to the Launch the MySQL Server Automatically option.

#### 2.3.6.11. The Security Options Dialog

It is strongly recommended that you set a `root` password for your MySQL server, and the MySQL Server Configuration Wizard requires by default that you do so. If you do not wish to set a `root` password, uncheck the box next to the Modify Security Settings option.

To set the `root` password, enter the desired password into both the New root password and Confirm boxes. If you are reconfiguring an existing server, you need to enter the existing `root` password into the Current root password box.

To prevent `root` logins from across the network, check the box next to the Root may only connect from localhost option. This increases the security of your `root` account.

To create an anonymous user account, check the box next to the Create An Anonymous Account option. Creating an anonymous account can decrease server security and cause login and permission difficulties. For this reason, it is not recommended.

#### 2.3.6.12. The Confirmation Dialog

The final dialog in the MySQL Server Configuration Wizard is the Confirmation Dialog. To start the configuration process, click the Execute button. To return to a previous dialog, click the Back button. To exit the MySQL Server Configuration Wizard without configuring the server, click the Cancel button.

After you click the Execute button, the MySQL Server Configuration Wizard performs a series of tasks and displays the progress onscreen as the tasks are performed.

The MySQL Server Configuration Wizard first determines configuration file options based on your choices using a template prepared by MySQL AB developers and engineers. This template is named `my-template.ini` and is located in your server installation directory.

The MySQL Configuration Wizard then writes these options to the corresponding configuration file.

If you chose to create a service for the MySQL server, the MySQL Server Configuration Wizard creates and starts the service. If you are reconfiguring an existing service, the MySQL Server Configuration Wizard restarts the service to apply your configuration changes.

If you chose to set a `root` password, the MySQL Configuration Wizard connects to the server, sets your new `root` password, and applies any other security settings you may have selected.

After the MySQL Server Configuration Wizard has completed its tasks, it displays a summary. Click the Finish button to exit the MySQL Server Configuration Wizard.

### 2.3.7. MySQL Network Service Agent

This section does not apply to MySQL Community Server users.

The MySQL Network Service Agent provides information to a MySQL Network Monitoring and Advisory Service Network Monitor about the health and statistics of your MySQL server. In order to use the service agent, you must have an instance of the MySQL Network Monitor installed. You will need the URL, including login and password, of the MySQL Network Monitor to complete this installation.

If you have selected that the MySQL Network Service Agent be installed automatically, you should follow the instructions below to install and configure the agent for your machine.

### Note

In the example screen shots below, the Linux version of the installer is shown. The basic process is identical for all platforms.

1. The MySQL Network Service Agent should start automatically. Click Forward or Next to start the installation process.

2. Choose an installation path for the MySQL Network Service Agent. This directory will contain the agent application and required components for the operation of the agent. You will need to know the location of this directory so that you can start and stop the agent when required.

   The default location under Linux is within the `/opt` directory; under Windows the default location is within the main MySQL installation directory (for example, `C:\Program Files\MySQL\MySQLNetwork\Agent`).

   Click Forward or Next to continue the installation process.

3. Enter the IP address or hostname of the MySQL server you want to monitor. By default, the localhost address (127.0.0.1) is used. This default value should be correct when MySQL Network Service Agent is installed as part of MySQL Enterprise, as you will be monitoring the local instance of the server. If you want validate the hostname or IP address, click the Yes radio button; otherwise, click the No button. If you have selected to validate the address then any problems be notified when you click Forward.

   Click Forward or Next to continue the installation process.

4. Enter the port number of the MySQL server that you want to monitor. The default value, 3306, should be correct unless you have altered the default value when running the MySQL Configuration Wizard during the installation of MySQL Enterprise.

   Click Forward or Next to continue the installation process.

5. Enter the user name the agent will use to connect to the server. You may use any user that has been configured on the MySQL server. You can even use the `root` password; however, the information will be stored within a standard text file in an unencrypted form. If you created an anonymous user during the Configuration Wizard process, you may use this user instead.

   Click Forward or Next to continue the installation process.

6. Enter the password for the user you selected in the previous step. You must enter the password twice to confirm the password.

   Click Forward or Next to continue the installation process.

7. Enter the host name of the machine that is running the MySQL Network Service Manager. You can locate this information in the `configuration_report.txt` file that was created when the MySQL Network Service Manager was installed. This file will be located in the directory where the MySQL Network Service Manager was installed, typically `/opt/mysqlnetwork-VERSION` (Linux) or `C:\Program Files\MySQL\Network`.

   Click Forward or Next to continue the installation process.

8. Enter the port number for the MySQL Network Service Manager.

   Click Forward or Next to continue the installation process.

9. Enter the user name the agent will use to connect to the MySQL Network Service Manager.

   Click Forward or Next to continue the installation process.

10. Enter the password required to connect to the MySQL Network Service Manager.

    Click Forward or Next to continue the installation process.

11. Enter the hostname that will be used to identify this MySQL server within the MySQL Network Service Manager.

    Click Forward or Next to continue the installation process.

12. Select the logging level to be used when reporting information to the MySQL Network Service Manager.

    Click Forward or Next to continue the installation process.

13. You are now ready to install the MySQL Service Agent. If you need to change any of the settings, use the Back button to go back to the configuration option you want to modify.

    Linux only: Before installation is started, you will be shown the process required to start the MySQL Agent. Make a note of this information, as you will need this to start the agent once it has been installed.

    Click Forward or Next to continue the installation process.

14. The installation process will start. It may take a few minutes to complete the installation of the MySQL Network Service Agent and configure the agent for your system.

    Click Forward or Nextto continue the installation process.

15. Once the process has been completed, click Finish to complete the installation and exit the installer.

For more information on the MySQL Network Monitoring and Advisory Service, see the corresponding documentation installed with MySQL Enterprise.

### 2.3.8. Upgrading MySQL Enterprise Server

This section does not apply to MySQL Community Server users.

When upgrading to MySQL Enterprise from Community Server you need only follow the installation process to install and upgrade the packages to the latest version provided by MySQL Enterprise. You will also need to install the latest MySQL Enterprise Service Pack and any outstanding MySQL Hot-fix packs.

Be aware, however, that you must take into account any of the changes when moving between major releases. You should also check the release notes (see Appendix E, MySQL Enterprise Release Notes) for details on major changes between revisions of MySQL Enterprise Server. For details of changes in other packages in MySQL Enterprise, see Appendix G, MySQL Change History.

You should also review the notes and advice contained within Section 2.4.16, “Upgrading MySQL”.

### 2.3.9. Uninstalling MySQL Enterprise

This section does not apply to MySQL Community Server users.

You can uninstall MySQL Enterprise using the standard tools according to your operating system.

### Note

When uninstalling, any data files created are not removed. You will need to separately remove these files to completely remove MySQL from your system.

#### 2.3.9.1. Uninstalling on Windows

To uninstall MySQL Enterprise on Windows you should use the Add or Remove Programs utility located within the Control Panel.

Packages within MySQL Enterprise must be removed individually. You may also use this option to remove packages that you no longer want or use.

Any data you created while MySQL Enterprise was installed will not be removed. You will need to separately delete this information.

#### 2.3.9.2. Uninstalling on Linux (RPMs)

To uninstall MySQL Enterprise on a Linux operating system that uses the RPM package format, you must remove each of the packages that were installed by the MySQL Enterprise Installer individually.

To do this, first obtain a list of the installed packages:

    shell> rpm -q -a|grep -i mysql
    mysql-docs-en-5.0.26-1
    MySQL-server-standard-5.0.26-0.rhel4
    mysql-connector-j-5.0.3-1
    MySQL-devel-standard-5.0.26-0.rhel4
    mysql-query-browser-5.0r4-1rhel4
    mysql-connector-odbc-3.51.12-1
    MySQL-client-standard-5.0.26-0.rhel4
    mysql-administrator-5.0r4-1rhel4
    mysql-gui-tools-5.0r4-1rhel4
    mysql-setup-wizard-1.0-1
    mysql-connector-net-1.0.7-1

You can remove these packages individually, or all together automatically, like this:

    shell> rpm -q -a|grep -i mysql|xargs rpm --erase

### 2.3.10. Enterprise Server Default Configuration

This section does not apply to MySQL Community Server users.

The default configuration parameters for Enterprise Server are shown in the following table. For more information on setting parameters for MySQL, see Chapter 5, Database Administration.

Parameter | Default value
`innodb_additional_mem_pool_size` | 8MB
`Innodb_buffer_pool_size` | 40MB
`innodb_log_buffer_size` | 8MB
`innodb_log_file_size` | 50MB
`key_buffer_size` | 40MB
`log_slow_queries` | 1
`long_query_time` | 1
`max_connections` | 200
`myisam_sort_buffer_size` | 40MB
`query_cache_size` | 20MB
`sort_buffer_size` | 1MB
`sql_mode` | `strict_trans_tables`, `no_zero_in_date`, `no_zero_date`,`error_for_division_by_zero`, `no_auto_create_user`, `real_as_float`, `ignore_space`
table_cache/table_open_cache | 512
table_definition_cache | 512
thread_cache | 100

## 2.4. Installing MySQL Community Server

### 2.4.1. Overview of MySQL Community Server Installation

1. Determine whether MySQL runs and is supported on your platform. Please note that not all platforms are equally suitable for running MySQL, and that not all platforms on which MySQL is known to run are officially supported by MySQL AB. For a list of platforms on which MySQL Community Server runs, see Section 2.4.2, “Operating Systems Supported by MySQL Community Server”.

2. Choose which distribution to install. Several versions of MySQL are available, and most are available in several distribution formats. You can choose from prepackaged distributions containing binary (precompiled) programs or source code. When in doubt, use a binary distribution. We also provide public access to our current source tree for those who want to see our most recent developments and help us test new code. To determine which version and type of distribution you should use, see Section 2.4.3, “Choosing Which MySQL Distribution to Install”.

3. Download the distribution that you want to install. For instructions, see Section 2.4.4, “How to Get MySQL”. To verify the integrity of the distribution, use the instructions in Section 2.4.5, “Verifying Package Integrity Using MD5 Checksums or `GnuPG`”.

4. Install the distribution. To install MySQL from a binary distribution, use the instructions in Section 2.4.7, “Standard MySQL Installation Using a Binary Distribution”. To install MySQL from a source distribution or from the current development source tree, use the instructions in Section 2.4.14, “MySQL Installation Using a Source Distribution”.

   If you encounter installation difficulties, see Section 2.4.18, “Operating System-Specific Notes”, for information on solving problems for particular platforms.

5. Perform any necessary post-installation setup. After installing MySQL, read Section 2.4.15, “Post-Installation Setup and Testing”. This section contains important information about making sure the MySQL server is working properly. It also describes how to secure the initial MySQL user accounts, which have no passwords until you assign passwords. The section applies whether you install MySQL using a binary or source distribution.

6. If you want to run the MySQL benchmark scripts, Perl support for MySQL must be available. See Section 2.4.19, “Perl Installation Notes”.

The immediately following sections contain the information necessary to choose, download, and verify your distribution. The instructions in later sections of the chapter describe how to install the distribution that you choose. For binary distributions, see the instructions at Section 2.4.7, “Standard MySQL Installation Using a Binary Distribution”. To build MySQL from source, use the instructions at Section 2.4.14, “MySQL Installation Using a Source Distribution”.

### 2.4.2. Operating Systems Supported by MySQL Community Server

This section does not apply to MySQL Enterprise Server users.

This section lists the operating systems on which MySQL Community Server is known to run.

Important: MySQL AB does not necessarily provide official support for all the platforms listed in this section. For information about those platforms which MySQL AB officially supports, see MySQL Server Supported Platforms on the MySQL Web site.

We use GNU Autoconf, so it is possible to port MySQL to all modern systems that have a C++ compiler and a working implementation of POSIX threads. (Thread support is needed for the server. To compile only the client code, the only requirement is a C++ compiler.) We use and develop the software ourselves primarily on Linux (SuSE and Red Hat), FreeBSD, and Sun Solaris (versions 8 and 9).

MySQL has been reported to compile successfully on the following combinations of operating system and thread package. Note that for many operating systems, native thread support works only in the latest versions.

- AIX 4.x, 5.x with native threads. See Section 2.4.18.5.3, “IBM-AIX notes”.

- Amiga.

- BSDI 2.x with the MIT-pthreads package. See Section 2.4.18.4.4, “BSD/OS Version 2.x Notes”.

- BSDI 3.0, 3.1 and 4.x with native threads. See Section 2.4.18.4.4, “BSD/OS Version 2.x Notes”.

- Digital Unix 4.x with native threads. See Section 2.4.18.5.5, “Alpha-DEC-UNIX Notes (Tru64)”.

- FreeBSD 2.x with the MIT-pthreads package. See Section 2.4.18.4.1, “FreeBSD Notes”.

- FreeBSD 3.x and 4.x with native threads. See Section 2.4.18.4.1, “FreeBSD Notes”.

- FreeBSD 4.x with LinuxThreads. See Section 2.4.18.4.1, “FreeBSD Notes”.

- HP-UX 10.20 with the DCE threads or the MIT-pthreads package. See Section 2.4.18.5.1, “HP-UX Version 10.20 Notes”.

- HP-UX 11.x with the native threads. See Section 2.4.18.5.2, “HP-UX Version 11.x Notes”.

- Linux 2.0+ with LinuxThreads 0.7.1+ or `glibc` 2.0.7+ for various CPU architectures. See Section 2.4.18.1, “Linux Notes”.

- Mac OS X. See Section 2.4.18.2, “Mac OS X Notes”.

- NetBSD 1.3/1.4 Intel and NetBSD 1.3 Alpha (requires GNU make). See Section 2.4.18.4.2, “NetBSD Notes”.

- Novell NetWare 6.0 and 6.5. See Section 2.4.12, “Installing MySQL on NetWare”.

- OpenBSD 2.5 and with native threads. OpenBSD earlier than 2.5 with the MIT-pthreads package. See Section 2.4.18.4.3, “OpenBSD 2.5 Notes”.

- OS/2 Warp 3, FixPack 29 and OS/2 Warp 4, FixPack 4. See Section 2.4.18.6, “OS/2 Notes”.

- SCO OpenServer 5.0.X with a recent port of the FSU Pthreads package. See Section 2.4.18.5.8, “SCO UNIX and OpenServer 5.0.x Notes”.

- SCO Openserver 6.0.x. See Section 2.4.18.5.9, “SCO OpenServer 6.0.x Notes”.

- SCO UnixWare 7.1.x. See Section 2.4.18.5.10, “SCO UnixWare 7.1.x and OpenUNIX 8.0.0 Notes”.

- SGI Irix 6.x with native threads. See Section 2.4.18.5.7, “SGI Irix Notes”.

- Solaris 2.5 and above with native threads on SPARC and x86. See Section 2.4.18.3, “Solaris Notes”.

- SunOS 4.x with the MIT-pthreads package. See Section 2.4.18.3, “Solaris Notes”.

- Tru64 Unix. See Section 2.4.18.5.5, “Alpha-DEC-UNIX Notes (Tru64)”.

- Windows 9x, Me, NT, 2000, XP, and Windows Server 2003. See Section 2.4.8, “Installing MySQL on Windows”.

Not all platforms are equally well suited for running MySQL. How well a certain platform is suited for a high-load mission-critical MySQL server is determined by the following factors:

- General stability of the thread library. A platform may have an excellent reputation otherwise, but MySQL is only as stable as the thread library it calls, even if everything else is perfect.

- The capability of the kernel and the thread library to take advantage of symmetric multi-processor (SMP) systems. In other words, when a process creates a thread, it should be possible for that thread to run on a CPU different from the original process.

- The capability of the kernel and the thread library to run many threads that acquire and release a mutex over a short critical region frequently without excessive context switches. If the implementation of `pthread_mutex_lock()` is too anxious to yield CPU time, this hurts MySQL tremendously. If this issue is not taken care of, adding extra CPUs actually makes MySQL slower.

- General filesystem stability and performance.

- If your tables are large, performance is affected by the ability of the filesystem to deal with large files at all and to deal with them efficiently.

- Our level of expertise here at MySQL AB with the platform. If we know a platform well, we enable platform-specific optimizations and fixes at compile time. We can also provide advice on configuring your system optimally for MySQL.

- The amount of testing we have done internally for similar configurations.

- The number of users that have run MySQL successfully on the platform in similar configurations. If this number is high, the likelihood of encountering platform-specific surprises is much smaller.

Based on the preceding criteria, the best platforms for running MySQL at this point are x86 with SuSE Linux using a 2.4 or 2.6 kernel, and ReiserFS (or any similar Linux distribution) and SPARC with Solaris (2.7-9). FreeBSD comes third, but we really hope it joins the top club once the thread library is improved. We also hope that at some point we are able to include into the top category all other platforms on which MySQL currently compiles and runs, but not quite with the same level of stability and performance. This requires some effort on our part in cooperation with the developers of the operating systems and library components that MySQL depends on. If you are interested in improving one of those components, are in a position to influence its development, and need more detailed instructions on what MySQL needs to run better, send an email message to the MySQL `internals` mailing list. See Section 1.7.1, “MySQL Mailing Lists”.

Please note that the purpose of the preceding comparison is not to say that one operating system is better or worse than another in general. We are talking only about choosing an OS for the specific purpose of running MySQL. With this in mind, the result of this comparison might be different if other factors were considered. In some cases, the reason one OS is better for MySQL than another might simply be that we have been able to put more effort into testing and optimizing for a particular platform. We are just stating our observations to help you decide which platform to use for running MySQL.

### 2.4.3. Choosing Which MySQL Distribution to Install

This section does not apply to MySQL Enterprise Server users.

When preparing to install MySQL, you should decide which version to use. MySQL development occurs in several release series, and you can pick the one that best fits your needs. After deciding which version to install, you can choose a distribution format. Releases are available in binary or source format.

#### 2.4.3.1. Choosing Which Version of MySQL to Install

This section does not apply to MySQL Enterprise Server users.

The first decision to make is whether you want to use a production (stable) release or a development release. In the MySQL development process, multiple release series co-exist, each at a different stage of maturity:

- MySQL 5.1 is the current development release series.

- MySQL 5.0 is the current stable (production-quality) release series. New releases are issued for bugfixes only; no new features are being added that could effect stability.

- MySQL 4.1 is the previous stable (production-quality) release series. New releases are issued for critical bugfixes and security fixes. No significant new features are to be added to this series.

- MySQL 4.0 and 3.23 are the old stable (production-quality) release series. These versions are now retired, so new releases are issued only to fix extremely critical bugs (primarily security issues).

We do not believe in a complete code freeze because this prevents us from making bugfixes and other fixes that must be done. By “somewhat frozen” we mean that we may add small things that should not affect anything that currently works in a production release. Naturally, relevant bugfixes from an earlier series propagate to later series.

Normally, if you are beginning to use MySQL for the first time or trying to port it to some system for which there is no binary distribution, we recommend going with the production release series. Currently, this is MySQL 5.0. All MySQL releases, even those from development series, are checked with the MySQL benchmarks and an extensive test suite before being issued.

If you are running an older system and want to upgrade, but do not want to take the chance of having a non-seamless upgrade, you should upgrade to the latest version in the same release series you are using (where only the last part of the version number is newer than yours). We have tried to fix only fatal bugs and make only small, relatively “safe” changes to that version.

If you want to use new features not present in the production release series, you can use a version from a development series. Note that development releases are not as stable as production releases.

If you want to use the very latest sources containing all current patches and bugfixes, you can use one of our BitKeeper repositories. These are not “releases” as such, but are available as previews of the code on which future releases are to be based.

The MySQL naming scheme uses release names that consist of three numbers and a suffix; for example, mysql-5.0.12-beta. The numbers within the release name are interpreted as follows:

- The first number (5) is the major version and describes the file format. All MySQL 5 releases have the same file format.

- The second number (0) is the release level. Taken together, the major version and release level constitute the release series number.

- The third number (12) is the version number within the release series. This is incremented for each new release. Usually you want the latest version for the series you have chosen.

For each minor update, the last number in the version string is incremented. When there are major new features or minor incompatibilities with previous versions, the second number in the version string is incremented. When the file format changes, the first number is increased.

Release names also include a suffix to indicates the stability level of the release. Releases within a series progress through a set of suffixes to indicate how the stability level improves. The possible suffixes are:

- alpha indicates that the release is for preview purposes only. Known bugs should be documented in the News section (see Appendix G, MySQL Change History). Most alpha releases implement new commands and extensions. Active development that may involve major code changes can occur in an alpha release. However, we do conduct testing before issuing a release.

- beta indicates that the release is appropriate for use with new development. Within beta releases, the features and compatibility should remain consistent. However, beta releases may contain numerous and major unaddressed bugs.

  All APIs, externally visible structures, and columns for SQL statements will not change during future beta, release candidate, or production releases.

- rc indicates a Release Candidate. Release candidates are believed to be stable, having passed all of MySQL's internal testing, and with all known fatal runtime bugs fixed. However, the release has not been in widespread use long enough to know for sure that all bugs have been identified. Only minor fixes are added. (A release candidate is what formerly was known as a gamma release.)

- If there is no suffix, it indicates that the release is a General Availability (GA) or Production release. GA releases are stable, having successfully passed through all earlier release stages and are believed to be reliable, free of serious bugs, and suitable for use in production systems. Only critical bugfixes are applied to the release.

MySQL uses a naming scheme that is slightly different from most other products. In general, it is usually safe to use any version that has been out for a couple of weeks without being replaced by a new version within the same release series.

All releases of MySQL are run through our standard tests and benchmarks to ensure that they are relatively safe to use. Because the standard tests are extended over time to check for all previously found bugs, the test suite keeps getting better.

All releases have been tested at least with these tools:

- An internal test suite

  The `mysql-test` directory contains an extensive set of test cases. We run these tests for every server binary. See Section 24.1.2, “MySQL Test Suite”, for more information about this test suite.

- The MySQL benchmark suite

  This suite runs a range of common queries. It is also a test to determine whether the latest batch of optimizations actually made the code faster. See Section 7.1.4, “The MySQL Benchmark Suite”.

- The `crash-me` test

  This test tries to determine what features the database supports and what its capabilities and limitations are. See Section 7.1.4, “The MySQL Benchmark Suite”.

We also test the newest MySQL version in our internal production environment, on at least one machine. We have more than 100GB of data to work with.

#### 2.4.3.2. Choosing a Distribution Format

This section does not apply to MySQL Enterprise Server users.

After choosing which version of MySQL to install, you should decide whether to use a binary distribution or a source distribution. In most cases, you should probably use a binary distribution, if one exists for your platform. Binary distributions are available in native format for many platforms, such as RPM files for Linux or PKG package installers for Mac OS X or Solaris. Distributions also are available as Zip archives or compressed tar files.

Reasons to choose a binary distribution include the following:

- Binary distributions generally are easier to install than source distributions.

- To satisfy different user requirements, we provide two different binary versions. One is compiled with the core feature set. The other (MySQL-Max) is compiled with an extended feature set. Both versions are compiled from the same source distribution. All native MySQL clients can connect to servers from either MySQL version.

  The extended MySQL binary distribution is identified by the `-max` suffix and is configured with the same options as mysqld-max. See Section 5.3, “The mysqld-max Extended MySQL Server”.

  For RPM distributions, if you want to use the `MySQL-Max` RPM, you must first install the standard `MySQL-server` RPM.

Under some circumstances, you may be better off installing MySQL from a source distribution:

- You want to install MySQL at some explicit location. The standard binary distributions are ready to run at any installation location, but you might require even more flexibility to place MySQL components where you want.

- You want to configure mysqld to ensure that features are available that might not be included in the standard binary distributions. Here is a list of the most common extra options that you may want to use to ensure feature availability:

  - `--with-berkeley-db` (not available on all platforms)

  - `--with-libwrap`

  - `--with-named-z-libs` (this is done for some of the binaries)

  - `--with-debug[=full]`

- You want to configure mysqld without some features that are included in the standard binary distributions. For example, distributions normally are compiled with support for all character sets. If you want a smaller MySQL server, you can recompile it with support for only the character sets you need.

- You have a special compiler (such as `pgcc`) or want to use compiler options that are better optimized for your processor. Binary distributions are compiled with options that should work on a variety of processors from the same processor family.

- You want to use the latest sources from one of the BitKeeper repositories to have access to all current bugfixes. For example, if you have found a bug and reported it to the MySQL development team, the bugfix is committed to the source repository and you can access it there. The bugfix does not appear in a release until a release actually is issued.

- You want to read (or modify) the C and C++ code that makes up MySQL. For this purpose, you should get a source distribution, because the source code is always the ultimate manual.

- Source distributions contain more tests and examples than binary distributions.

#### 2.4.3.3. How and When Updates Are Released

MySQL is evolving quite rapidly and we want to share new developments with other MySQL users. We try to produce a new release whenever we have new and useful features that others also seem to have a need for.

We also try to help users who request features that are easy to implement. We take note of what our licensed users want, and we especially take note of what our support customers want and try to help them in this regard.

No one is required to download a new release. The News section helps you determine whether the new release has something you really want. See Appendix G, MySQL Change History.

We use the following policy when updating MySQL:

- Enterprise Server releases are meant to appear every 18 months, supplemented by quarterly service packs and monthly rapid updates. Community Server releases are meant to appear 2–3 times per year.

- Releases are issued within each series. Enterprise Server releases are numbered using even numbers (for example, 5.0.20). Community Server releases are numbered using odd numbers (for example, 5.0.21).

- Binary distributions for some platforms are made by us for major releases. Other people may make binary distributions for other systems, but probably less frequently.

- We make fixes available as soon as we have identified and corrected small or non-critical but annoying bugs. The fixes are available in source form immediately from our public BitKeeper repositories, and are included in the next release.

- If by any chance a security vulnerability or critical bug is found in a release, our policy is to fix it in a new release as soon as possible. (We would like other companies to do this, too!)

#### 2.4.3.4. Release Philosophy—No Known Bugs in Releases

This section does not apply to MySQL Enterprise Server users.

We put considerable time and effort into making our releases bug-free. Our policy is never to release a version of MySQL intended for production use that has any known fatal, repeatable bugs.

We have documented all open problems, bugs, and issues that are dependent on design decisions. See Section B.8, “Known Issues in MySQL”.

Our aim is to fix everything that is fixable without making a stable MySQL version less stable. In certain cases, this means we can fix an issue in the development versions, but not in the stable (production) version. Naturally, we document such issues so that users are aware of them.

Here is a description of our build process:

- We monitor bugs from our customer support list, the bugs database at http://bugs.mysql.com/, and the MySQL external mailing lists.

- All reported bugs for live versions are entered into the bugs database.

- When we fix a bug, we always try to make a test case for it and include it into our test system to ensure that the bug can never recur without being detected. (About 90% of all fixed bugs have test cases.)

- We create test cases for each new feature that we add to MySQL.

- Before we start to build a new MySQL release, we ensure that all reported repeatable bugs for that MySQL version (3.23.x, 4.0.x, 4.1.x, 5.0.x, 5.1.x, and so on) are fixed. If something is impossible to fix due to some internal design decision in MySQL, we document this in the manual. See Section B.8, “Known Issues in MySQL”.

- We do a build on all platforms for which we support binaries and run our test suite and benchmark suite on all of them.

- We do not publish a binary for a platform for which the test or benchmark suite fails. If the problem is due to a general error in the source, we fix it and do the build plus tests on all systems again from scratch.

- The build and test process takes a week. If we receive a report regarding a fatal bug during this process (for example, one that causes a core dump), we fix the problem and restart the build process.

- After publishing the binaries on http://dev.mysql.com/, we send out an announcement message to the `mysql` and `announce` mailing lists. See Section 1.7.1, “MySQL Mailing Lists”. The announcement message contains a list of all changes to the release and any known problems with the release. The Known Problems section in the release notes has been needed for only a handful of releases.

- To quickly give our users access to the latest MySQL features, we try to produce a new MySQL release every 4-8 weeks. Source code snapshots are built daily and are available at http://downloads.mysql.com/snapshots.php.

- If, despite our best efforts, we receive any bug reports after a release is issued that a critical problem exists for the build on a specific platform, we fix it at once and build a new `'a'` release for that platform. Thanks to our large user base, problems are found and resolved very quickly.

- Our track record for making stable releases is quite good. In the last 150 releases, we had to do a new build for fewer than 10 of them. In three of these cases, the bug was a faulty `glibc` library on one of our build machines that took us a long time to track down.

#### 2.4.3.5. MySQL Binaries Compiled by MySQL AB

This section does not apply to MySQL Enterprise Server users.

As a service of MySQL AB, we provide a set of binary distributions of MySQL that are compiled on systems at our site or on systems where supporters of MySQL kindly have given us access to their machines.

In addition to the binaries provided in platform-specific package formats, we offer binary distributions for a number of platforms in the form of compressed tar files (`.tar.gz` files). See Section 2.4.7, “Standard MySQL Installation Using a Binary Distribution”.

The RPM distributions for MySQL 5.0 releases that we make available through our Web site are generated by MySQL AB.

For Windows distributions, see Section 2.4.8, “Installing MySQL on Windows”.

These distributions are generated using the script `Build-tools/Do-compile`, which compiles the source code and creates the binary `tar.gz` archive using scripts/make_binary_distribution.

These binaries are configured and built with the following compilers and options. This information can also be obtained by looking at the variables `COMP_ENV_INFO` and `CONFIGURE_LINE` inside the script bin/mysqlbug of every binary tar file distribution.

Anyone who has more optimal options for any of the following `configure` commands can mail them to the MySQL `internals` mailing list. See Section 1.7.1, “MySQL Mailing Lists”.

If you want to compile a debug version of MySQL, you should add `--with-debug` or `--with-debug=full` to the following configure commands and remove any `-fomit-frame-pointer` options.

The following binaries are built on MySQL AB development systems:

- Linux 2.4.xx x86 with gcc 2.95.3:

      CFLAGS="-O2 -mcpu=pentiumpro" CXX=gcc CXXFLAGS="-O2 -mcpu=pentiumpro
      -felide-constructors" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --enable-assembler --disable-shared
      --with-client-ldflags=-all-static --with-mysqld-ldflags=-all-static

- Linux 2.4.x x86 with icc (Intel C++ Compiler 8.1 or later releases):

      CC=icc CXX=icpc CFLAGS="-O3 -unroll2 -ip -mp -no-gcc -restrict"
      CXXFLAGS="-O3 -unroll2 -ip -mp -no-gcc -restrict" ./configure
      --prefix=/usr/local/mysql --localstatedir=/usr/local/mysql/data
      --libexecdir=/usr/local/mysql/bin --with-extra-charsets=complex
      --enable-thread-safe-client --enable-local-infile --enable-assembler
      --disable-shared --with-client-ldflags=-all-static
      --with-mysqld-ldflags=-all-static --with-embedded-server --with-innodb

  Note that versions 8.1 and newer of the Intel compiler have separate drivers for 'pure' C (`icc`) and C++ (`icpc`); if you use icc version 8.0 or older for building MySQL, you will need to set `CXX=icc`.

- Linux 2.4.xx Intel Itanium 2 with ecc (Intel C++ Itanium Compiler 7.0):

      CC=ecc CFLAGS="-O2 -tpp2 -ip -nolib_inline" CXX=ecc CXXFLAGS="-O2
      -tpp2 -ip -nolib_inline" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile

- Linux 2.4.xx Intel Itanium with ecc (Intel C++ Itanium Compiler 7.0):

      CC=ecc CFLAGS=-tpp1 CXX=ecc CXXFLAGS=-tpp1 ./configure
      --prefix=/usr/local/mysql --with-extra-charsets=complex
      --enable-thread-safe-client --enable-local-infile

- Linux 2.4.xx alpha with `ccc` (Compaq C V6.2-505 / Compaq C++ V6.3-006):

      CC=ccc CFLAGS="-fast -arch generic" CXX=cxx CXXFLAGS="-fast -arch
      generic -noexceptions -nortti" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --with-mysqld-ldflags=-non_shared
      --with-client-ldflags=-non_shared --disable-shared

- Linux 2.x.xx ppc with gcc 2.95.4:

      CC=gcc CFLAGS="-O3 -fno-omit-frame-pointer" CXX=gcc CXXFLAGS="-O3
      -fno-omit-frame-pointer -felide-constructors -fno-exceptions
      -fno-rtti" ./configure --prefix=/usr/local/mysql
      --localstatedir=/usr/local/mysql/data --libexecdir=/usr/local/mysql/bin
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --disable-shared --with-embedded-server
      --with-innodb

- Linux 2.4.xx s390 with gcc 2.95.3:

      CFLAGS="-O2" CXX=gcc CXXFLAGS="-O2 -felide-constructors" ./configure
      --prefix=/usr/local/mysql --with-extra-charsets=complex
      --enable-thread-safe-client --enable-local-infile --disable-shared
      --with-client-ldflags=-all-static --with-mysqld-ldflags=-all-static

- Linux 2.4.xx x86_64 (AMD64) with gcc 3.2.1:

      CXX=gcc ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --disable-shared

- Sun Solaris 8 x86 with gcc 3.2.3:

      CC=gcc CFLAGS="-O3 -fno-omit-frame-pointer" CXX=gcc CXXFLAGS="-O3
      -fno-omit-frame-pointer -felide-constructors -fno-exceptions
      -fno-rtti" ./configure --prefix=/usr/local/mysql
      --localstatedir=/usr/local/mysql/data --libexecdir=/usr/local/mysql/bin
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --disable-shared --with-innodb

- Sun Solaris 8 SPARC with gcc 3.2:

      CC=gcc CFLAGS="-O3 -fno-omit-frame-pointer" CXX=gcc CXXFLAGS="-O3
      -fno-omit-frame-pointer -felide-constructors -fno-exceptions
      -fno-rtti" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --enable-assembler --with-named-z-libs=no
      --with-named-curses-libs=-lcurses --disable-shared

- Sun Solaris 8 SPARC 64-bit with gcc 3.2:

      CC=gcc CFLAGS="-O3 -m64 -fno-omit-frame-pointer" CXX=gcc CXXFLAGS="-O3
      -m64 -fno-omit-frame-pointer -felide-constructors -fno-exceptions
      -fno-rtti" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --with-named-z-libs=no
      --with-named-curses-libs=-lcurses --disable-shared

- Sun Solaris 9 SPARC with gcc 2.95.3:

      CC=gcc CFLAGS="-O3 -fno-omit-frame-pointer" CXX=gcc CXXFLAGS="-O3
      -fno-omit-frame-pointer -felide-constructors -fno-exceptions
      -fno-rtti" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --enable-assembler --with-named-curses-libs=-lcurses
      --disable-shared

- Sun Solaris 9 SPARC with `cc-5.0` (Sun Forte 5.0):

      CC=cc-5.0 CXX=CC ASFLAGS="-xarch=v9" CFLAGS="-Xa -xstrconst -mt
      -D_FORTEC_ -xarch=v9" CXXFLAGS="-noex -mt -D_FORTEC_ -xarch=v9"
      ./configure --prefix=/usr/local/mysql --with-extra-charsets=complex
      --enable-thread-safe-client --enable-local-infile --enable-assembler
      --with-named-z-libs=no --enable-thread-safe-client --disable-shared

- IBM AIX 4.3.2 ppc with gcc 3.2.3:

      CFLAGS="-O2 -mcpu=powerpc -Wa,-many " CXX=gcc CXXFLAGS="-O2
      -mcpu=powerpc -Wa,-many -felide-constructors -fno-exceptions
      -fno-rtti" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --with-named-z-libs=no --disable-shared

- IBM AIX 4.3.3 ppc with `xlC_r` (IBM Visual Age C/C++ 6.0):

      CC=xlc_r CFLAGS="-ma -O2 -qstrict -qoptimize=2 -qmaxmem=8192"
      CXX=xlC_r CXXFLAGS ="-ma -O2 -qstrict -qoptimize=2 -qmaxmem=8192"
      ./configure --prefix=/usr/local/mysql --localstatedir=/usr/local/mysql/data
      --libexecdir=/usr/local/mysql/bin --with-extra-charsets=complex
      --enable-thread-safe-client --enable-local-infile --with-named-z-libs=no
      --disable-shared --with-innodb

- IBM AIX 5.1.0 ppc with gcc 3.3:

      CFLAGS="-O2 -mcpu=powerpc -Wa,-many" CXX=gcc CXXFLAGS="-O2 -mcpu=powerpc
      -Wa,-many -felide-constructors -fno-exceptions -fno-rtti" ./configure
      --prefix=/usr/local/mysql --with-extra-charsets=complex
      --enable-thread-safe-client --enable-local-infile --with-named-z-libs=no
      --disable-shared

- IBM AIX 5.2.0 ppc with `xlC_r` (IBM Visual Age C/C++ 6.0):

      CC=xlc_r CFLAGS="-ma -O2 -qstrict -qoptimize=2 -qmaxmem=8192"
      CXX=xlC_r CXXFLAGS="-ma -O2 -qstrict -qoptimize=2 -qmaxmem=8192"
      ./configure --prefix=/usr/local/mysql --localstatedir=/usr/local/mysql/data
      --libexecdir=/usr/local/mysql/bin --with-extra-charsets=complex
      --enable-thread-safe-client --enable-local-infile --with-named-z-libs=no
      --disable-shared --with-embedded-server --with-innodb

- HP-UX 10.20 pa-risc1.1 with gcc 3.1:

      CFLAGS="-DHPUX -I/opt/dce/include -O3 -fPIC" CXX=gcc CXXFLAGS="-DHPUX
      -I/opt/dce /include -felide-constructors -fno-exceptions -fno-rtti
      -O3 -fPIC" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --with-pthread --with-named-thread-libs=-ldce
      --with-lib-ccflags=-fPIC --disable-shared

- HP-UX 11.00 pa-risc with `aCC` (HP ANSI C++ B3910B A.03.50):

      CC=cc CXX=aCC CFLAGS=+DAportable CXXFLAGS=+DAportable ./configure
      --prefix=/usr/local/mysql --localstatedir=/usr/local/mysql/data
      --libexecdir=/usr/local/mysql/bin --with-extra-charsets=complex
      --enable-thread-safe-client --enable-local-infile --disable-shared
      --with-embedded-server --with-innodb

- HP-UX 11.11 pa-risc2.0 64bit with `aCC` (HP ANSI C++ B3910B A.03.33):

      CC=cc CXX=aCC CFLAGS=+DD64 CXXFLAGS=+DD64 ./configure
      --prefix=/usr/local/mysql --with-extra-charsets=complex
      --enable-thread-safe-client --enable-local-infile --disable-shared

- HP-UX 11.11 pa-risc2.0 32bit with `aCC` (HP ANSI C++ B3910B A.03.33):

      CC=cc CXX=aCC CFLAGS="+DAportable" CXXFLAGS="+DAportable" ./configure
      --prefix=/usr/local/mysql --localstatedir=/usr/local/mysql/data
      --libexecdir=/usr/local/mysql/bin --with-extra-charsets=complex
      --enable-thread-safe-client --enable-local-infile --disable-shared
      --with-innodb

- HP-UX 11.22 ia64 64bit with `aCC` (HP aC++/ANSI C B3910B A.05.50):

      CC=cc CXX=aCC CFLAGS="+DD64 +DSitanium2" CXXFLAGS="+DD64 +DSitanium2"
      ./configure --prefix=/usr/local/mysql --localstatedir=/usr/local/mysql/data
      --libexecdir=/usr/local/mysql/bin --with-extra-charsets=complex
      --enable-thread-safe-client --enable-local-infile --disable-shared
      --with-embedded-server --with-innodb

- Apple Mac OS X 10.2 powerpc with gcc 3.1:

      CC=gcc CFLAGS="-O3 -fno-omit-frame-pointer" CXX=gcc CXXFLAGS="-O3
      -fno-omit-frame-pointer -felide-constructors -fno-exceptions
      -fno-rtti" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --disable-shared

- FreeBSD 4.7 i386 with gcc 2.95.4:

      CFLAGS=-DHAVE_BROKEN_REALPATH ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --enable-assembler --with-named-z-libs=not-used
      --disable-shared

- FreeBSD 4.7 i386 using LinuxThreads with gcc 2.95.4:

      CFLAGS="-DHAVE_BROKEN_REALPATH -D__USE_UNIX98 -D_REENTRANT
      -D_THREAD_SAFE -I/usr/local/include/pthread/linuxthreads"
      CXXFLAGS="-DHAVE_BROKEN_REALPATH -D__USE_UNIX98 -D_REENTRANT
      -D_THREAD_SAFE -I/usr/local/include/pthread/linuxthreads" ./configure
      --prefix=/usr/local/mysql --localstatedir=/usr/local/mysql/data
      --libexecdir=/usr/local/mysql/bin --enable-thread-safe-client
      --enable-local-infile --enable-assembler
      --with-named-thread-libs="-DHAVE_GLIBC2_STYLE_GETHOSTBYNAME_R
      -D_THREAD_SAFE -I /usr/local/include/pthread/linuxthreads
      -L/usr/local/lib -llthread -llgcc_r" --disable-shared
      --with-embedded-server --with-innodb

- QNX Neutrino 6.2.1 i386 with gcc 2.95.3qnx-nto 20010315:

      CC=gcc CFLAGS="-O3 -fno-omit-frame-pointer" CXX=gcc CXXFLAGS="-O3
      -fno-omit-frame-pointer -felide-constructors -fno-exceptions
      -fno-rtti" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --disable-shared

The following binaries are built on third-party systems kindly provided to MySQL AB by other users. These are provided only as a courtesy; MySQL AB does not have full control over these systems, so we can provide only limited support for the binaries built on them.

- SCO Unix 3.2v5.0.7 i386 with gcc 2.95.3:

      CFLAGS="-O3 -mpentium" LDFLAGS=-static CXX=gcc CXXFLAGS="-O3 -mpentium
      -felide-constructors" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --with-named-z-libs=no --enable-thread-safe-client
      --disable-shared

- SCO UnixWare 7.1.4 i386 with CC 3.2:

      CC=cc CFLAGS="-O" CXX=CC ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --with-named-z-libs=no --enable-thread-safe-client
      --disable-shared --with-readline

- SCO OpenServer 6.0.0 i386 with CC 3.2:

      CC=cc CFLAGS="-O" CXX=CC ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --with-named-z-libs=no --enable-thread-safe-client
      --disable-shared --with-readline

- Compaq Tru64 OSF/1 V5.1 732 alpha with `cc/cxx` (Compaq C V6.3-029i / DIGITAL C++ V6.1-027):

      CC="cc -pthread" CFLAGS="-O4 -ansi_alias -ansi_args -fast -inline
      speed -speculate all" CXX="cxx -pthread" CXXFLAGS="-O4 -ansi_alias
      -fast -inline speed -speculate all -noexceptions -nortti" ./configure
      --prefix=/usr/local/mysql --with-extra-charsets=complex
      --enable-thread-safe-client --enable-local-infile
      --with-named-thread-libs="-lpthread -lmach -lexc -lc" --disable-shared
      --with-mysqld-ldflags=-all-static

- SGI Irix 6.5 IP32 with gcc 3.0.1:

      CC=gcc CFLAGS="-O3 -fno-omit-frame-pointer" CXXFLAGS="-O3
      -fno-omit-frame-pointer -felide-constructors -fno-exceptions
      -fno-rtti" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --disable-shared

- FreeBSD/sparc64 5.0 with gcc 3.2.1:

      CFLAGS=-DHAVE_BROKEN_REALPATH ./configure --prefix=/usr/local/mysql
      --localstatedir=/usr/local/mysql/data --libexecdir=/usr/local/mysql/bin
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --disable-shared --with-innodb

The following compile options have been used for binary packages that MySQL AB provided in the past. These binaries no longer are being updated, but the compile options are listed here for reference purposes.

- Linux 2.2.xx SPARC with egcs 1.1.2:

      CC=gcc CFLAGS="-O3 -fno-omit-frame-pointer" CXX=gcc CXXFLAGS="-O3
      -fno-omit-frame-pointer -felide-constructors -fno-exceptions
      -fno-rtti" ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex --enable-thread-safe-client
      --enable-local-infile --enable-assembler --disable-shared

- Linux 2.2.x with x686 with gcc 2.95.2:

      CFLAGS="-O3 -mpentiumpro" CXX=gcc CXXFLAGS="-O3 -mpentiumpro
      -felide-constructors -fno-exceptions -fno-rtti" ./configure
      --prefix=/usr/local/mysql --enable-assembler
      --with-mysqld-ldflags=-all-static --disable-shared
      --with-extra-charsets=complex

- SunOS 4.1.4 2 sun4c with gcc 2.7.2.1:

      CC=gcc CXX=gcc CXXFLAGS="-O3 -felide-constructors" ./configure
      --prefix=/usr/local/mysql --disable-shared --with-extra-charsets=complex
      --enable-assembler

- SunOS 5.5.1 (and above) sun4u with egcs 1.0.3a or 2.90.27 or gcc 2.95.2 and newer:

      CC=gcc CFLAGS="-O3" CXX=gcc CXXFLAGS="-O3 -felide-constructors
      -fno-exceptions -fno-rtti" ./configure --prefix=/usr/local/mysql
      --with-low-memory --with-extra-charsets=complex --enable-assembler

- SunOS 5.6 i86pc with gcc 2.8.1:

      CC=gcc CXX=gcc CXXFLAGS=-O3 ./configure --prefix=/usr/local/mysql
      --with-low-memory --with-extra-charsets=complex

- BSDI BSD/OS 3.1 i386 with gcc 2.7.2.1:

      CC=gcc CXX=gcc CXXFLAGS=-O ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex

- BSDI BSD/OS 2.1 i386 with gcc 2.7.2:

      CC=gcc CXX=gcc CXXFLAGS=-O3 ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex

- AIX 4.2 with gcc 2.7.2.2:

      CC=gcc CXX=gcc CXXFLAGS=-O3 ./configure --prefix=/usr/local/mysql
      --with-extra-charsets=complex

### 2.4.4. How to Get MySQL

This section does not apply to MySQL Enterprise Server users.

Check our downloads page at http://dev.mysql.com/downloads/ for information about the current version of MySQL and for downloading instructions. For a complete up-to-date list of MySQL download mirror sites, see http://dev.mysql.com/downloads/mirrors.html. You can also find information there about becoming a MySQL mirror site and how to report a bad or out-of-date mirror.

Our main mirror is located at http://mirrors.sunsite.dk/mysql/.

### 2.4.5. Verifying Package Integrity Using MD5 Checksums or `GnuPG`

This section does not apply to MySQL Enterprise Server users.

After you have downloaded the MySQL package that suits your needs and before you attempt to install it, you should make sure that it is intact and has not been tampered with. MySQL AB offers three means of integrity checking:

- MD5 checksums

- Cryptographic signatures using `GnuPG`, the GNU Privacy Guard

- For RPM packages, the built-in RPM integrity verification mechanism

The following sections describe how to use these methods.

If you notice that the MD5 checksum or GPG signatures do not match, first try to download the respective package one more time, perhaps from another mirror site. If you repeatedly cannot successfully verify the integrity of the package, please notify us about such incidents, including the full package name and the download site you have been using, at `<webmaster@mysql.com>` or `<build@mysql.com>`. Do not report downloading problems using the bug-reporting system.

#### 2.4.5.1. Verifying the MD5 Checksum

This section does not apply to MySQL Enterprise Server users.

After you have downloaded a MySQL package, you should make sure that its MD5 checksum matches the one provided on the MySQL download pages. Each package has an individual checksum that you can verify with the following command, where `package_name` is the name of the package you downloaded:

    shell> md5sum package_name

Example:

    shell> md5sum mysql-standard-5.0.34-linux-i686.tar.gz
    aaab65abbec64d5e907dcd41b8699945  mysql-standard-5.0.34-linux-i686.tar.gz

You should verify that the resulting checksum (the string of hexadecimal digits) matches the one displayed on the download page immediately below the respective package.

Note: Make sure to verify the checksum of the archive file (for example, the `.zip` or `.tar.gz` file) and not of the files that are contained inside of the archive.

Note that not all operating systems support the md5sum command. On some, it is simply called md5, and others do not ship it at all. On Linux, it is part of the GNU Text Utilities package, which is available for a wide range of platforms. You can download the source code from http://www.gnu.org/software/textutils/ as well. If you have OpenSSL installed, you can use the command openssl md5 `package_name` instead. A Windows implementation of the md5 command line utility is available from http://www.fourmilab.ch/md5/. winMd5Sum is a graphical MD5 checking tool that can be obtained from http://www.nullriver.com/index/products/winmd5sum.

#### 2.4.5.2. Signature Checking Using `GnuPG`

This section does not apply to MySQL Enterprise Server users.

Another method of verifying the integrity and authenticity of a package is to use cryptographic signatures. This is more reliable than using MD5 checksums, but requires more work.

At MySQL AB, we sign MySQL downloadable packages with GnuPG (GNU Privacy Guard). GnuPG is an Open Source alternative to the well-known Pretty Good Privacy (PGP) by Phil Zimmermann. See http://www.gnupg.org/ for more information about GnuPG and how to obtain and install it on your system. Most Linux distributions ship with GnuPG installed by default. For more information about GnuPG, see http://www.openpgp.org/.

To verify the signature for a specific package, you first need to obtain a copy of MySQL AB's public GPG build key, which you can download from http://www.keyserver.net/. The key that you want to obtain is named `build@mysql.com`. Alternatively, you can cut and paste the key directly from the following text:

    Key ID:
    pub  1024D/5072E1F5 2003-02-03
         MySQL Package signing key (www.mysql.com) <build@mysql.com>
    Fingerprint: A4A9 4068 76FC BD3C 4567  70C8 8C71 8D3B 5072 E1F5

    Public Key (ASCII-armored):

    -----BEGIN PGP PUBLIC KEY BLOCK-----
    Version: GnuPG v1.0.6 (GNU/Linux)
    Comment: For info see http://www.gnupg.org

    mQGiBD4+owwRBAC14GIfUfCyEDSIePvEW3SAFUdJBtoQHH/nJKZyQT7h9bPlUWC3
    RODjQReyCITRrdwyrKUGku2FmeVGwn2u2WmDMNABLnpprWPkBdCk96+OmSLN9brZ
    fw2vOUgCmYv2hW0hyDHuvYlQA/BThQoADgj8AW6/0Lo7V1W9/8VuHP0gQwCgvzV3
    BqOxRznNCRCRxAuAuVztHRcEAJooQK1+iSiunZMYD1WufeXfshc57S/+yeJkegNW
    hxwR9pRWVArNYJdDRT+rf2RUe3vpquKNQU/hnEIUHJRQqYHo8gTxvxXNQc7fJYLV
    K2HtkrPbP72vwsEKMYhhr0eKCbtLGfls9krjJ6sBgACyP/Vb7hiPwxh6rDZ7ITnE
    kYpXBACmWpP8NJTkamEnPCia2ZoOHODANwpUkP43I7jsDmgtobZX9qnrAXw+uNDI
    QJEXM6FSbi0LLtZciNlYsafwAPEOMDKpMqAK6IyisNtPvaLd8lH0bPAnWqcyefep
    rv0sxxqUEMcM3o7wwgfN83POkDasDbs3pjwPhxvhz6//62zQJ7Q7TXlTUUwgUGFj
    a2FnZSBzaWduaW5nIGtleSAod3d3Lm15c3FsLmNvbSkgPGJ1aWxkQG15c3FsLmNv
    bT6IXQQTEQIAHQUCPj6jDAUJCWYBgAULBwoDBAMVAwIDFgIBAheAAAoJEIxxjTtQ
    cuH1cY4AnilUwTXn8MatQOiG0a/bPxrvK/gCAJ4oinSNZRYTnblChwFaazt7PF3q
    zIhMBBMRAgAMBQI+PqPRBYMJZgC7AAoJEElQ4SqycpHyJOEAn1mxHijft00bKXvu
    cSo/pECUmppiAJ41M9MRVj5VcdH/KN/KjRtW6tHFPYhMBBMRAgAMBQI+QoIDBYMJ
    YiKJAAoJELb1zU3GuiQ/lpEAoIhpp6BozKI8p6eaabzF5MlJH58pAKCu/ROofK8J
    Eg2aLos+5zEYrB/LsrkCDQQ+PqMdEAgA7+GJfxbMdY4wslPnjH9rF4N2qfWsEN/l
    xaZoJYc3a6M02WCnHl6ahT2/tBK2w1QI4YFteR47gCvtgb6O1JHffOo2HfLmRDRi
    Rjd1DTCHqeyX7CHhcghj/dNRlW2Z0l5QFEcmV9U0Vhp3aFfWC4Ujfs3LU+hkAWzE
    7zaD5cH9J7yv/6xuZVw411x0h4UqsTcWMu0iM1BzELqX1DY7LwoPEb/O9Rkbf4fm
    Le11EzIaCa4PqARXQZc4dhSinMt6K3X4BrRsKTfozBu74F47D8Ilbf5vSYHbuE5p
    /1oIDznkg/p8kW+3FxuWrycciqFTcNz215yyX39LXFnlLzKUb/F5GwADBQf+Lwqq
    a8CGrRfsOAJxim63CHfty5mUc5rUSnTslGYEIOCR1BeQauyPZbPDsDD9MZ1ZaSaf
    anFvwFG6Llx9xkU7tzq+vKLoWkm4u5xf3vn55VjnSd1aQ9eQnUcXiL4cnBGoTbOW
    I39EcyzgslzBdC++MPjcQTcA7p6JUVsP6oAB3FQWg54tuUo0Ec8bsM8b3Ev42Lmu
    QT5NdKHGwHsXTPtl0klk4bQk4OajHsiy1BMahpT27jWjJlMiJc+IWJ0mghkKHt92
    6s/ymfdf5HkdQ1cyvsz5tryVI3Fx78XeSYfQvuuwqp2H139pXGEkg0n6KdUOetdZ
    Whe70YGNPw1yjWJT1IhMBBgRAgAMBQI+PqMdBQkJZgGAAAoJEIxxjTtQcuH17p4A
    n3r1QpVC9yhnW2cSAjq+kr72GX0eAJ4295kl6NxYEuFApmr1+0uUq/SlsQ==
    =YJkx
    -----END PGP PUBLIC KEY BLOCK-----

To import the build key into your personal public GPG keyring, use gpg --import. For example, if you have saved the key in a file named `mysql_pubkey.asc`, the import command looks like this:

    shell> gpg --import mysql_pubkey.asc

After you have downloaded and imported the public build key, download your desired MySQL package and the corresponding signature, which also is available from the download page. The signature file has the same name as the distribution file with an `.asc` extension. For example:

Distribution file | `mysql-standard-5.0.34-linux-i686.tar.gz`
Signature file | `mysql-standard-5.0.34-linux-i686.tar.gz.asc`

Make sure that both files are stored in the same directory and then run the following command to verify the signature for the distribution file:

    shell> gpg --verify package_name.asc

Example:

    shell> gpg --verify mysql-standard-5.0.34-linux-i686.tar.gz.asc
    gpg: Signature made Tue 12 Jul 2005 23:35:41 EST using DSA key ID 5072E1F5
    gpg: Good signature from "MySQL Package signing key (www.mysql.com) <build@mysql.com>"

The `Good signature` message indicates that everything is all right. You can ignore any `insecure memory` warning you might obtain.

See the GPG documentation for more information on how to work with public keys.

#### 2.4.5.3. Signature Checking Using `RPM`

This section does not apply to MySQL Enterprise Server users.

For RPM packages, there is no separate signature. RPM packages have a built-in GPG signature and MD5 checksum. You can verify a package by running the following command:

    shell> rpm --checksig package_name.rpm

Example:

    shell> rpm --checksig MySQL-server-5.0.34-0.i386.rpm
    MySQL-server-5.0.34-0.i386.rpm: md5 gpg OK

Note: If you are using RPM 4.1 and it complains about `(GPG) NOT OK (MISSING KEYS: GPG#5072e1f5)`, even though you have imported the MySQL public build key into your own GPG keyring, you need to import the key into the RPM keyring first. RPM 4.1 no longer uses your personal GPG keyring (or GPG itself). Rather, it maintains its own keyring because it is a system-wide application and a user's GPG public keyring is a user-specific file. To import the MySQL public key into the RPM keyring, first obtain the key as described in Section 2.4.5.2, “Signature Checking Using `GnuPG`”. Then use rpm --import to import the key. For example, if you have saved the public key in a file named `mysql_pubkey.asc`, import it using this command:

    shell> rpm --import mysql_pubkey.asc

If you need to obtain the MySQL public key, see Section 2.4.5.2, “Signature Checking Using `GnuPG`”.

### 2.4.6. Installation Layouts

This section describes the default layout of the directories created by installing binary or source distributions provided by MySQL AB. A distribution provided by another vendor might use a layout different from those shown here.

For MySQL 5.0 on Windows, the default installation directory is `C:\Program Files\MySQL\MySQL Server 5.0`. (Some Windows users prefer to install in `C:\mysql`, the directory that formerly was used as the default. However, the layout of the subdirectories remains the same.) The installation directory has the following subdirectories:

Directory | Contents of Directory
`bin` | Client programs and the mysqld server
`data` | Log files, databases
`Docs` | Manual in CHM format
`examples` | Example programs and scripts
`include` | Include (header) files
`lib` | Libraries
`scripts` | Utility scripts
`share` | Error message files

Installations created from MySQL AB's Linux RPM distributions result in files under the following system directories:

Directory | Contents of Directory
`/usr/bin` | Client programs and scripts
`/usr/sbin` | The mysqld server
`/var/lib/mysql` | Log files, databases
`/usr/share/info` | Manual in Info format
`/usr/share/man` | Unix manual pages
`/usr/include/mysql` | Include (header) files
`/usr/lib/mysql` | Libraries
`/usr/share/mysql` | Error message and character set files
`/usr/share/sql-bench` | Benchmarks

On Unix, a tar file binary distribution is installed by unpacking it at the installation location you choose (typically `/usr/local/mysql`) and creates the following directories in that location:

Directory | Contents of Directory
`bin` | Client programs and the mysqld server
`data` | Log files, databases
`docs` | Manual in Info format
`man` | Unix manual pages
`include` | Include (header) files
`lib` | Libraries
`scripts` | mysql_install_db
`share/mysql` | Error message files
`sql-bench` | Benchmarks

A source distribution is installed after you configure and compile it. By default, the installation step installs files under `/usr/local`, in the following subdirectories:

Directory | Contents of Directory
`bin` | Client programs and scripts
`include/mysql` | Include (header) files
`Docs` | Manual in Info, CHM formats
`man` | Unix manual pages
`lib/mysql` | Libraries
`libexec` | The mysqld server
`share/mysql` | Error message files
`sql-bench` | Benchmarks and `crash-me` test
`var` | Databases and log files

Within its installation directory, the layout of a source installation differs from that of a binary installation in the following ways:

- The mysqld server is installed in the `libexec` directory rather than in the `bin` directory.

- The data directory is `var` rather than `data`.

- mysql_install_db is installed in the `bin` directory rather than in the `scripts` directory.

- The header file and library directories are `include/mysql` and `lib/mysql` rather than `include` and `lib`.

You can create your own binary installation from a compiled source distribution by executing the `scripts/make_binary_distribution` script from the top directory of the source distribution.

### 2.4.7. Standard MySQL Installation Using a Binary Distribution

This section does not apply to MySQL Enterprise Server users.

The next several sections cover the installation of MySQL on platforms where we offer packages using the native packaging format of the respective platform. (This is also known as performing a “binary install.”) However, binary distributions of MySQL are available for many other platforms as well. See Section 2.4.13, “Installing MySQL on Other Unix-Like Systems”, for generic installation instructions for these packages that apply to all platforms.

See Section 2.4, “Installing MySQL Community Server”, for more information on what other binary distributions are available and how to obtain them.

### 2.4.8. Installing MySQL on Windows

This section does not apply to MySQL Enterprise Server users.

A native Windows distribution of MySQL has been available from MySQL AB since version 3.21 and represents a sizable percentage of the daily downloads of MySQL. This section describes the process for installing MySQL on Windows.

Note: If you are upgrading MySQL from an existing installation older than MySQL 4.1.5, you must first perform the the procedure described in Section 2.4.8.14, “Upgrading MySQL on Windows”.

To run MySQL on Windows, you need the following:

- A 32-bit Windows operating system such as 9x, Me, NT, 2000, XP, or Windows Server 2003.

  A Windows NT-based operating system (NT, 2000, XP, 2003) permits you to run the MySQL server as a service. The use of a Windows NT-based operating system is strongly recommended. See Section 2.4.8.11, “Starting MySQL as a Windows Service”.

  Generally, you should install MySQL on Windows using an account that has administrator rights. Otherwise, you may encounter problems with certain operations such as editing the `PATH` environment variable or accessing the Service Control Manager.

- TCP/IP protocol support.

- Enough space on the hard drive to unpack, install, and create the databases in accordance with your requirements (generally a minimum of 200 megabytes is recommended.)

There may also be other requirements, depending on how you plan to use MySQL:

- If you plan to connect to the MySQL server via ODBC, you need a Connector/ODBC driver. See Chapter 23, Connectors.

- If you need tables with a size larger than 4GB, install MySQL on an NTFS or newer filesystem. Don't forget to use `MAX_ROWS` and `AVG_ROW_LENGTH` when you create tables. See Section 13.1.5, “`CREATE TABLE` Syntax”.

MySQL for Windows is available in several distribution formats:

- Binary distributions are available that contain a setup program that installs everything you need so that you can start the server immediately. Another binary distribution format contains an archive that you simply unpack in the installation location and then configure yourself. For details, see Section 2.4.8.1, “Choosing An Installation Package”.

- The source distribution contains all the code and support files for building the executables using the Visual Studio compiler system.

Generally speaking, you should use a binary distribution that includes an installer. It is simpler to use than the others, and you need no additional tools to get MySQL up and running. The installer for the Windows version of MySQL, combined with a GUI Configuration Wizard, automatically installs MySQL, creates an option file, starts the server, and secures the default user accounts.

The following section describes how to install MySQL on Windows using a binary distribution. To use an installation package that does not include an installer, follow the procedure described in Section 2.4.8.5, “Installing MySQL from a Noinstall Zip Archive”. To install using a source distribution, see Section 2.4.14.6, “Installing MySQL from Source on Windows”.

MySQL distributions for Windows can be downloaded from http://dev.mysql.com/downloads/. See Section 2.4.4, “How to Get MySQL”.

#### 2.4.8.1. Choosing An Installation Package

This section does not apply to MySQL Enterprise Server users.

For MySQL 5.0, there are three installation packages to choose from when installing MySQL on Windows:

- The Essentials Package: This package has a filename similar to `mysql-essential-5.0.34-win32.msi` and contains the minimum set of files needed to install MySQL on Windows, including the Configuration Wizard. This package does not include optional components such as the embedded server and benchmark suite.

- The Complete Package: This package has a filename similar to `mysql-5.0.34-win32.zip` and contains all files needed for a complete Windows installation, including the Configuration Wizard. This package includes optional components such as the embedded server and benchmark suite.

- The Noinstall Archive: This package has a filename similar to `mysql-noinstall-5.0.34-win32.zip` and contains all the files found in the Complete install package, with the exception of the Configuration Wizard. This package does not include an automated installer, and must be manually installed and configured.

The Essentials package is recommended for most users. It is provided as an `.msi` file for use with the Windows Installer. The Complete and Noinstall distributions are packaged as Zip archives. To use them, you must have a tool that can unpack `.zip` files.

Your choice of install package affects the installation process you must follow. If you choose to install either the Essentials or Complete install packages, see Section 2.4.8.2, “Installing MySQL with the Automated Installer”. If you choose to install MySQL from the Noinstall archive, see Section 2.4.8.5, “Installing MySQL from a Noinstall Zip Archive”.

#### 2.4.8.2. Installing MySQL with the Automated Installer

New MySQL users can use the MySQL Installation Wizard and MySQL Configuration Wizard to install MySQL on Windows. These are designed to install and configure MySQL in such a way that new users can immediately get started using MySQL.

The MySQL Installation Wizard and MySQL Configuration Wizard are available in the Essentials and Complete install packages. They are recommended for most standard MySQL installations. Exceptions include users who need to install multiple instances of MySQL on a single server host and advanced users who want complete control of server configuration.

#### 2.4.8.3. Using the MySQL Installation Wizard

##### 2.4.8.3.1. Introduction to the Installation Wizard

MySQL Installation Wizard is an installer for the MySQL server that uses the latest installer technologies for Microsoft Windows. The MySQL Installation Wizard, in combination with the MySQL Configuration Wizard, allows a user to install and configure a MySQL server that is ready for use immediately after installation.

The MySQL Installation Wizard is the standard installer for all MySQL server distributions, version 4.1.5 and higher. Users of previous versions of MySQL need to shut down and remove their existing MySQL installations manually before installing MySQL with the MySQL Installation Wizard. See Section 2.4.8.3.7, “Upgrading MySQL with the Installation Wizard”, for more information on upgrading from a previous version.

Microsoft has included an improved version of their Microsoft Windows Installer (MSI) in the recent versions of Windows. MSI has become the de-facto standard for application installations on Windows 2000, Windows XP, and Windows Server 2003. The MySQL Installation Wizard makes use of this technology to provide a smoother and more flexible installation process.

The Microsoft Windows Installer Engine was updated with the release of Windows XP; those using a previous version of Windows can reference this Microsoft Knowledge Base article for information on upgrading to the latest version of the Windows Installer Engine.

In addition, Microsoft has introduced the WiX (Windows Installer XML) toolkit recently. This is the first highly acknowledged Open Source project from Microsoft. We have switched to WiX because it is an Open Source project and it allows us to handle the complete Windows installation process in a flexible manner using scripts.

Improving the MySQL Installation Wizard depends on the support and feedback of users like you. If you find that the MySQL Installation Wizard is lacking some feature important to you, or if you discover a bug, please report it in our bugs database using the instructions given in Section 1.8, “How to Report Bugs or Problems”.

##### 2.4.8.3.2. Downloading and Starting the MySQL Installation Wizard

This section does not apply to MySQL Enterprise Server users.

The MySQL installation packages can be downloaded from http://dev.mysql.com/downloads/. If the package you download is contained within a Zip archive, you need to extract the archive first.

The process for starting the wizard depends on the contents of the installation package you download. If there is a `setup.exe` file present, double-click it to start the installation process. If there is an `.msi` file present, double-click it to start the installation process.

##### 2.4.8.3.3. Choosing an Install Type

This section does not apply to MySQL Enterprise Server users.

There are three installation types available: Typical, Complete, and Custom.

The Typical installation type installs the MySQL server, the mysql command-line client, and the command-line utilities. The command-line clients and utilities include mysqldump, myisamchk, and several other tools to help you manage the MySQL server.

The Complete installation type installs all components included in the installation package. The full installation package includes components such as the embedded server library, the benchmark suite, support scripts, and documentation.

The Custom installation type gives you complete control over which packages you wish to install and the installation path that is used. See Section 2.4.8.3.4, “The Custom Install Dialog”, for more information on performing a custom install.

If you choose the Typical or Complete installation types and click the Next button, you advance to the confirmation screen to verify your choices and begin the installation. If you choose the Custom installation type and click the Next button, you advance to the custom installation dialog, described in Section 2.4.8.3.4, “The Custom Install Dialog”.

##### 2.4.8.3.4. The Custom Install Dialog

This section does not apply to MySQL Enterprise Server users.

If you wish to change the installation path or the specific components that are installed by the MySQL Installation Wizard, choose the Custom installation type.

A tree view on the left side of the custom install dialog lists all available components. Components that are not installed have a red X icon; components that are installed have a gray icon. To change whether a component is installed, click on that component's icon and choose a new option from the drop-down list that appears.

You can change the default installation path by clicking the Change... button to the right of the displayed installation path.

After choosing your installation components and installation path, click the Next button to advance to the confirmation dialog.

##### 2.4.8.3.5. The Confirmation Dialog

This section does not apply to MySQL Enterprise Server users.

Once you choose an installation type and optionally choose your installation components, you advance to the confirmation dialog. Your installation type and installation path are displayed for you to review.

To install MySQL if you are satisfied with your settings, click the Install button. To change your settings, click the Back button. To exit the MySQL Installation Wizard without installing MySQL, click the Cancel button.

After installation is complete, you have the option of registering with the MySQL web site. Registration gives you access to post in the MySQL forums at forums.mysql.com, along with the ability to report bugs at bugs.mysql.com and to subscribe to our newsletter. The final screen of the installer provides a summary of the installation and gives you the option to launch the MySQL Configuration Wizard, which you can use to create a configuration file, install the MySQL service, and configure security settings.

##### 2.4.8.3.6. Changes Made by MySQL Installation Wizard

This section does not apply to MySQL Enterprise Server users.

Once you click the Install button, the MySQL Installation Wizard begins the installation process and makes certain changes to your system which are described in the sections that follow.

Changes to the Registry

The MySQL Installation Wizard creates one Windows registry key in a typical install situation, located in `HKEY_LOCAL_MACHINE\SOFTWARE\MySQL AB`.

The MySQL Installation Wizard creates a key named after the major version of the server that is being installed, such as `MySQL Server 5.0`. It contains two string values, `Location` and `Version`. The `Location` string contains the path to the installation directory. In a default installation it contains `C:\Program Files\MySQL\MySQL Server 5.0\`. The `Version` string contains the release number. For example, for an installation of MySQL Server 5.0.34, the key contains a value of `5.0.34`.

These registry keys are used to help external tools identify the installed location of the MySQL server, preventing a complete scan of the hard-disk to determine the installation path of the MySQL server. The registry keys are not required to run the server, and if you install MySQL using the `noinstall` Zip archive, the registry keys are not created.

Changes to the Start Menu

The MySQL Installation Wizard creates a new entry in the Windows Start menu under a common MySQL menu heading named after the major version of MySQL that you have installed. For example, if you install MySQL 5.0, the MySQL Installation Wizard creates a MySQL Server 5.0 section in the Start menu.

The following entries are created within the new Start menu section:

- MySQL Command Line Client: This is a shortcut to the mysql command-line client and is configured to connect as the `root` user. The shortcut prompts for a `root` user password when you connect.

- MySQL Server Instance Config Wizard: This is a shortcut to the MySQL Configuration Wizard. Use this shortcut to configure a newly installed server, or to reconfigure an existing server.

- MySQL Documentation: This is a link to the MySQL server documentation that is stored locally in the MySQL server installation directory. This option is not available when the MySQL server is installed using the Essentials installation package.

Changes to the File System

The MySQL Installation Wizard by default installs the MySQL 5.0 server to `C:\`Program Files`\MySQL\MySQL Server `5.0``, where `Program Files` is the default location for applications in your system, and `5.0` is the major version of your MySQL server. This is the recommended location for the MySQL server, replacing the former default location `C:\mysql`.

By default, all MySQL applications are stored in a common directory at `C:\`Program Files`\MySQL`, where `Program Files` is the default location for applications in your Windows installation. A typical MySQL installation on a developer machine might look like this:

    C:\Program Files\MySQL\MySQL Server 5.0
    C:\Program Files\MySQL\MySQL Administrator 1.0
    C:\Program Files\MySQL\MySQL Query Browser 1.0

This approach makes it easier to manage and maintain all MySQL applications installed on a particular system.

##### 2.4.8.3.7. Upgrading MySQL with the Installation Wizard

This section does not apply to MySQL Enterprise Server users.

The MySQL Installation Wizard can perform server upgrades automatically using the upgrade capabilities of MSI. That means you do not need to remove a previous installation manually before installing a new release. The installer automatically shuts down and removes the previous MySQL service before installing the new version.

Automatic upgrades are available only when upgrading between installations that have the same major and minor version numbers. For example, you can upgrade automatically from MySQL 4.1.5 to MySQL 4.1.6, but not from MySQL 4.1 to MySQL 5.0.

See Section 2.4.8.14, “Upgrading MySQL on Windows”.

#### 2.4.8.4. MySQL Windows Configuration Wizard

For instructions on using the MySQL Configuration Wizard for Wizard to configure your MySQL server, see Section 2.3.6, “MySQL Server Configuration Wizard”.

#### 2.4.8.5. Installing MySQL from a Noinstall Zip Archive

This section does not apply to MySQL Enterprise Server users.

Users who are installing from the Noinstall package can use the instructions in this section to manually install MySQL. The process for installing MySQL from a Zip archive is as follows:

1. Extract the archive to the desired install directory

2. Create an option file

3. Choose a MySQL server type

4. Start the MySQL server

5. Secure the default user accounts

This process is described in the sections that follow.

#### 2.4.8.6. Extracting the Install Archive

This section does not apply to MySQL Enterprise Server users.

To install MySQL manually, do the following:

1. If you are upgrading from a previous version please refer to Section 2.4.8.14, “Upgrading MySQL on Windows”, before beginning the upgrade process.

2. If you are using a Windows NT-based operating system such as Windows NT, Windows 2000, Windows XP, or Windows Server 2003, make sure that you are logged in as a user with administrator privileges.

3. Choose an installation location. Traditionally, the MySQL server is installed in `C:\mysql`. The MySQL Installation Wizard installs MySQL under `C:\Program Files\MySQL`. If you do not install MySQL at `C:\mysql`, you must specify the path to the install directory during startup or in an option file. See Section 2.4.8.7, “Creating an Option File”.

4. Extract the install archive to the chosen installation location using your preferred Zip archive tool. Some tools may extract the archive to a folder within your chosen installation location. If this occurs, you can move the contents of the subfolder into the chosen installation location.

#### 2.4.8.7. Creating an Option File

If you need to specify startup options when you run the server, you can indicate them on the command line or place them in an option file. For options that are used every time the server starts, you may find it most convenient to use an option file to specify your MySQL configuration. This is particularly true under the following circumstances:

- The installation or data directory locations are different from the default locations (`C:\Program Files\MySQL\MySQL Server 5.0` and `C:\Program Files\MySQL\MySQL Server 5.0\data`).

- You need to tune the server settings.

When the MySQL server starts on Windows, it looks for options in two files: the `my.ini` file in the Windows directory, and the `C:\my.cnf` file. The Windows directory typically is named something like `C:\WINDOWS` or `C:\WINNT`. You can determine its exact location from the value of the `WINDIR` environment variable using the following command:

    C:\> echo %WINDIR%

MySQL looks for options first in the `my.ini` file, and then in the `my.cnf` file. However, to avoid confusion, it's best if you use only one file. If your PC uses a boot loader where `C:` is not the boot drive, your only option is to use the `my.ini` file. Whichever option file you use, it must be a plain text file.

You can also make use of the example option files included with your MySQL distribution; see Section 4.3.2.1, “Preconfigured Option Files”.

An option file can be created and modified with any text editor, such as Notepad. For example, if MySQL is installed in `E:\mysql` and the data directory is in `E:\mydata\data`, you can create an option file containing a `[mysqld]` section to specify values for the `basedir` and `datadir` parameters:

    [mysqld]
    # set basedir to your installation path
    basedir=E:/mysql
    # set datadir to the location of your data directory
    datadir=E:/mydata/data

Note that Windows pathnames are specified in option files using (forward) slashes rather than backslashes. If you do use backslashes, you must double them:

    [mysqld]
    # set basedir to your installation path
    basedir=E:\\mysql
    # set datadir to the location of your data directory
    datadir=E:\\mydata\\data

On Windows, the MySQL installer places the data directory directly under the directory where you install MySQL. If you would like to use a data directory in a different location, you should copy the entire contents of the `data` directory to the new location. For example, if MySQL is installed in `C:\Program Files\MySQL\MySQL Server 5.0`, the data directory is by default in `C:\Program Files\MySQL\MySQL Server 5.0\data`. If you want to use `E:\mydata` as the data directory instead, you must do two things:

1. Move the entire `data` directory and all of its contents from `C:\Program Files\MySQL\MySQL Server 5.0\data` to `E:\mydata`.

2. Use a `--datadir` option to specify the new data directory location each time you start the server.

#### 2.4.8.8. Selecting a MySQL Server type

This section does not apply to MySQL Enterprise Server users.

The following table shows the available servers for Windows in MySQL 5.0:

Binary | Description
mysqld-debug | Compiled with full debugging and automatic memory allocation checking, as well as `InnoDB` and `BDB` support.
mysqld | Optimized binary with `InnoDB` support.
mysqld-nt | Optimized binary for Windows NT, 2000, and XP with support for named pipes.
mysqld-max | Optimized binary with `InnoDB` and `BDB` support.
mysqld-max-nt | Like mysqld-max, but compiled with support for named pipes.

All of the preceding binaries are optimized for modern Intel processors, but should work on any Intel i386-class or higher processor.

All Windows MySQL 5.0 servers have support for symbolic linking of database directories.

MySQL supports TCP/IP on all Windows platforms. The mysqld-nt and `mysql-max-nt` servers support named pipes on Windows NT, 2000, XP, and 2003. However, the default is to use TCP/IP regardless of platform. (Named pipes are slower than TCP/IP in many Windows configurations.)

Use of named pipes is subject to these conditions:

- Named pipes are enabled only if you start the server with the `--enable-named-pipe` option. It is necessary to use this option explicitly because some users have experienced problems with shutting down the MySQL server when named pipes were used.

- Named-pipe connections are allowed only by the mysqld-nt or mysqld-max-nt servers, and only if the server is run on a version of Windows that supports named pipes (NT, 2000, XP, 2003).

- These servers can be run on Windows 98 or Me, but only if TCP/IP is installed; named-pipe connections cannot be used.

- These servers cannot be run on Windows 95.

Note: Most of the examples in this manual use mysqld as the server name. If you choose to use a different server, such as mysqld-nt, make the appropriate substitutions in the commands that are shown in the examples.

#### 2.4.8.9. Starting the Server for the First Time

This section gives a general overview of starting the MySQL server. The following sections provide more specific information for starting the MySQL server from the command line or as a Windows service.

The information here applies primarily if you installed MySQL using the `Noinstall` version, or if you wish to configure and test MySQL manually rather than with the GUI tools.

The examples in these sections assume that MySQL is installed under the default location of `C:\Program Files\MySQL\MySQL Server 5.0`. Adjust the pathnames shown in the examples if you have MySQL installed in a different location.

On NT-based systems such as Windows NT, 2000, XP, or 2003, clients have two options. They can use TCP/IP, or they can use a named pipe if the server supports named-pipe connections. For MySQL to work with TCP/IP on Windows NT 4, you must install service pack 3 (or newer).

On Windows 95, 98, or Me, MySQL clients always connect to the server using TCP/IP. (This allows any machine on your network to connect to your MySQL server.) Because of this, you must make sure that TCP/IP support is installed on your machine before starting MySQL. You can find TCP/IP on your Windows CD-ROM.

Note that if you are using an old Windows 95 release (for example, OSR2), it is likely that you have an old Winsock package; MySQL requires Winsock 2. You can get the newest Winsock from http://www.microsoft.com/. Windows 98 has the new Winsock 2 library, so it is unnecessary to update the library.

MySQL for Windows also supports shared-memory connections if the server is started with the `--shared-memory` option. Clients can connect through shared memory by using the `--protocol=memory` option.

For information about which server binary to run, see Section 2.4.8.8, “Selecting a MySQL Server type”.

Testing is best done from a command prompt in a console window (or “DOS window”). In this way you can have the server display status messages in the window where they are easy to see. If something is wrong with your configuration, these messages make it easier for you to identify and fix any problems.

To start the server, enter this command:

    C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld" --console

For a server that includes `InnoDB` support, you should see the messages similar to those following as it starts (the pathnames and sizes may differ):

    InnoDB: The first specified datafile c:\ibdata\ibdata1 did not exist:
    InnoDB: a new database to be created!
    InnoDB: Setting file c:\ibdata\ibdata1 size to 209715200
    InnoDB: Database physically writes the file full: wait...
    InnoDB: Log file c:\iblogs\ib_logfile0 did not exist: new to be created
    InnoDB: Setting log file c:\iblogs\ib_logfile0 size to 31457280
    InnoDB: Log file c:\iblogs\ib_logfile1 did not exist: new to be created
    InnoDB: Setting log file c:\iblogs\ib_logfile1 size to 31457280
    InnoDB: Log file c:\iblogs\ib_logfile2 did not exist: new to be created
    InnoDB: Setting log file c:\iblogs\ib_logfile2 size to 31457280
    InnoDB: Doublewrite buffer not found: creating new
    InnoDB: Doublewrite buffer created
    InnoDB: creating foreign key constraint system tables
    InnoDB: foreign key constraint system tables created
    011024 10:58:25  InnoDB: Started

When the server finishes its startup sequence, you should see something like this, which indicates that the server is ready to service client connections:

    mysqld: ready for connections
    Version: '5.0.34'  socket: ''  port: 3306

The server continues to write to the console any further diagnostic output it produces. You can open a new console window in which to run client programs.

If you omit the `--console` option, the server writes diagnostic output to the error log in the data directory (`C:\Program Files\MySQL\MySQL Server 5.0\data` by default). The error log is the file with the `.err` extension.

Note: The accounts that are listed in the MySQL grant tables initially have no passwords. After starting the server, you should set up passwords for them using the instructions in Section 2.4.15, “Post-Installation Setup and Testing”.

#### 2.4.8.10. Starting MySQL from the Windows Command Line

The MySQL server can be started manually from the command line. This can be done on any version of Windows.

To start the mysqld server from the command line, you should start a console window (or “DOS window”) and enter this command:

    C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld"

The path to mysqld may vary depending on the install location of MySQL on your system.

On non-NT versions of Windows, this command starts mysqld in the background. That is, after the server starts, you should see another command prompt. If you start the server this way on Windows NT, 2000, XP, or 2003, the server runs in the foreground and no command prompt appears until the server exits. Because of this, you should open another console window to run client programs while the server is running.

You can stop the MySQL server by executing this command:

    C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqladmin" -u root shutdown

Note: If the MySQL `root` user account has a password, you need to invoke mysqladmin with the `-p` option and supply the password when prompted.

This command invokes the MySQL administrative utility mysqladmin to connect to the server and tell it to shut down. The command connects as the MySQL `root` user, which is the default administrative account in the MySQL grant system. Note that users in the MySQL grant system are wholly independent from any login users under Windows.

If mysqld doesn't start, check the error log to see whether the server wrote any messages there to indicate the cause of the problem. The error log is located in the `C:\Program Files\MySQL\MySQL Server 5.0\data` directory. It is the file with a suffix of `.err`. You can also try to start the server as mysqld --console; in this case, you may get some useful information on the screen that may help solve the problem.

The last option is to start mysqld with the `--standalone` and `--debug` options. In this case, mysqld writes a log file `C:\mysqld.trace` that should contain the reason why mysqld doesn't start. See Section H.1.2, “Creating Trace Files”.

Use mysqld --verbose --help to display all the options that mysqld understands.

#### 2.4.8.11. Starting MySQL as a Windows Service

On the NT family (Windows NT, 2000, XP, 2003), the recommended way to run MySQL is to install it as a Windows service, whereby MySQL starts and stops automatically when Windows starts and stops. A MySQL server installed as a service can also be controlled from the command line using NET commands, or with the graphical Services utility.

The Services utility (the Windows Service Control Manager) can be found in the Windows Control Panel (under Administrative Tools on Windows 2000, XP, and Server 2003). To avoid conflicts, it is advisable to close the Services utility while performing server installation or removal operations from the command line.

Before installing MySQL as a Windows service, you should first stop the current server if it is running by using the following command:

    C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqladmin" -u root shutdown

Note: If the MySQL `root` user account has a password, you need to invoke mysqladmin with the `-p` option and supply the password when prompted.

This command invokes the MySQL administrative utility mysqladmin to connect to the server and tell it to shut down. The command connects as the MySQL `root` user, which is the default administrative account in the MySQL grant system. Note that users in the MySQL grant system are wholly independent from any login users under Windows.

Install the server as a service using this command:

    C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld" --install

The service-installation command does not start the server. Instructions for that are given later in this section.

To make it easier to invoke MySQL programs, you can add the pathname of the MySQL `bin` directory to your Windows system `PATH` environment variable:

- On the Windows desktop, right-click on the My Computer icon, and select Properties

- Next select the Advanced tab from the System Properties menu that appears, and click the Environment Variables button.

- Under System Variables, select Path, and then click the Edit button. The Edit System Variable dialogue should appear.

- Place your cursor at the end of the text appearing in the space marked Variable Value. (Use the End key to ensure that your cursor is positioned at the very end of the text in this space.) Then enter the complete pathname of your MySQL `bin` directory (for example, `C:\Program Files\MySQL\MySQL Server 5.0\bin`), Note that there should be a semicolon separating this path from any values present in this field. Dismiss this dialogue, and each dialogue in turn, by clicking OK until all of the dialogues that were opened have been dismissed. You should now be able to invoke any MySQL executable program by typing its name at the DOS prompt from any directory on the system, without having to supply the path. This includes the servers, the mysql client, and all MySQL command-line utilities such as mysqladmin and mysqldump.

  You should not add the MySQL `bin` directory to your Windows `PATH` if you are running multiple MySQL servers on the same machine.

Warning: You must exercise great care when editing your system `PATH` by hand; accidental deletion or modification of any portion of the existing `PATH` value can leave you with a malfunctioning or even unusable system.

The following additional arguments can be used in MySQL 5.0 when installing the service:

- You can specify a service name immediately following the `--install` option. The default service name is `MySQL`.

- If a service name is given, it can be followed by a single option. By convention, this should be `--defaults-file=`file_name`` to specify the name of an option file from which the server should read options when it starts.

  It is possible to use a single option other than `--defaults-file`, but this is discouraged. `--defaults-file` is more flexible because it enables you to specify multiple startup options for the server by placing them in the named option file. Also, in MySQL 5.0, use of an option different from `--defaults-file` is not supported until 5.0.3.

- As of MySQL 5.0.1, you can also specify a `--local-service` option following the service name. This causes the server to run using the `LocalService` Windows account that has limited system privileges. This account is available only for Windows XP or newer. If both `--defaults-file` and `--local-service` are given following the service name, they can be in any order.

For a MySQL server that is installed as a Windows service, the following rules determine the service name and option files that the server uses:

- If the service-installation command specifies no service name or the default service name (`MySQL`) following the `--install` option, the server uses the a service name of `MySQL` and reads options from the `[mysqld]` group in the standard option files.

- If the service-installation command specifies a service name other than `MySQL` following the `--install` option, the server uses that service name. It reads options from the group that has the same name as the service, and reads options from the standard option files.

  The server also reads options from the `[mysqld]` group from the standard option files. This allows you to use the `[mysqld]` group for options that should be used by all MySQL services, and an option group with the same name as a service for use by the server installed with that service name.

- If the service-installation command specifies a `--defaults-file` option after the service name, the server reads options only from the `[mysqld]` group of the named file and ignores the standard option files.

As a more complex example, consider the following command:

    C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld"
              --install MySQL --defaults-file=C:\my-opts.cnf

Here, the default service name (`MySQL`) is given after the `--install` option. If no `--defaults-file` option had been given, this command would have the effect of causing the server to read the `[mysqld]` group from the standard option files. However, because the `--defaults-file` option is present, the server reads options from the `[mysqld]` option group, and only from the named file.

You can also specify options as Start parameters in the Windows Services utility before you start the MySQL service.

Once a MySQL server has been installed as a service, Windows starts the service automatically whenever Windows starts. The service also can be started immediately from the Services utility, or by using a NET START MySQL command. The NET command is not case sensitive.

When run as a service, mysqld has no access to a console window, so no messages can be seen there. If mysqld does not start, check the error log to see whether the server wrote any messages there to indicate the cause of the problem. The error log is located in the MySQL data directory (for example, `C:\Program Files\MySQL\MySQL Server 5.0\data`). It is the file with a suffix of `.err`.

When a MySQL server has been installed as a service, and the service is running, Windows stops the service automatically when Windows shuts down. The server also can be stopped manually by using the `Services` utility, the NET STOP MySQL command, or the mysqladmin shutdown command.

You also have the choice of installing the server as a manual service if you do not wish for the service to be started automatically during the boot process. To do this, use the `--install-manual` option rather than the `--install` option:

    C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld" --install-manual

To remove a server that is installed as a service, first stop it if it is running by executing NET STOP MySQL. Then use the `--remove` option to remove it:

    C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld" --remove

If mysqld is not running as a service, you can start it from the command line. For instructions, see Section 2.4.8.10, “Starting MySQL from the Windows Command Line”.

Please see Section 2.4.8.13, “Troubleshooting a MySQL Installation Under Windows”, if you encounter difficulties during installation.

#### 2.4.8.12. Testing The MySQL Installation

You can test whether the MySQL server is working by executing any of the following commands:

    C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqlshow"
    C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqlshow" -u root mysql
    C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqladmin" version status proc
    C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysql" test

If mysqld is slow to respond to TCP/IP connections from client programs, there is probably a problem with your DNS. In this case, start mysqld with the `--skip-name-resolve` option and use only `localhost` and IP numbers in the `Host` column of the MySQL grant tables.

You can force a MySQL client to use a named-pipe connection rather than TCP/IP by specifying the `--pipe` or `--protocol=PIPE` option, or by specifying `.` (period) as the host name. Use the `--socket` option to specify the name of the pipe if you do not want to use the default pipe name.

Note that if you have set a password for the `root` account, deleted the anonymous account, or created a new user account, then you must use the appropriate `-u` and `-p` options with the commands shown above in order to connect with the MySQL Server. See Section 5.8.4, “Connecting to the MySQL Server”.

For more information about mysqlshow, see Section 8.16, “mysqlshow — Display Database, Table, and Column Information”.

#### 2.4.8.13. Troubleshooting a MySQL Installation Under Windows

When installing and running MySQL for the first time, you may encounter certain errors that prevent the MySQL server from starting. The purpose of this section is to help you diagnose and correct some of these errors.

Your first resource when troubleshooting server issues is the error log. The MySQL server uses the error log to record information relevant to the error that prevents the server from starting. The error log is located in the data directory specified in your `my.ini` file. The default data directory location is `C:\Program Files\MySQL\MySQL Server 5.0\data`. See Section 5.12.1, “The Error Log”.

Another source of information regarding possible errors is the console messages displayed when the MySQL service is starting. Use the NET START MySQL command from the command line after installing mysqld as a service to see any error messages regarding the starting of the MySQL server as a service. See Section 2.4.8.11, “Starting MySQL as a Windows Service”.

The following examples show other common error messages you may encounter when installing MySQL and starting the server for the first time:

- If the MySQL server cannot find the `mysql` privileges database or other critical files, you may see these messsages:

      System error 1067 has occurred.
      Fatal error: Can't open privilege tables: Table 'mysql.host' doesn't exist

  These messages often occur when the MySQL base or data directories are installed in different locations than the default locations (`C:\Program Files\MySQL\MySQL Server 5.0` and `C:\Program Files\MySQL\MySQL Server 5.0\data`, respectively).

  This situation may occur when MySQL is upgraded and installed to a new location, but the configuration file is not updated to reflect the new location. In addition, there may be old and new configuration files that conflict. Be sure to delete or rename any old configuration files when upgrading MySQL.

  If you have installed MySQL to a directory other than `C:\Program Files\MySQL\MySQL Server 5.0`, you need to ensure that the MySQL server is aware of this through the use of a configuration (`my.ini`) file. The `my.ini` file needs to be located in your Windows directory, typically `C:\WINDOWS` or `C:\WINNT`. You can determine its exact location from the value of the `WINDIR` environment variable by issuing the following command from the command prompt:

      C:\> echo %WINDIR%

  An option file can be created and modified with any text editor, such as Notepad. For example, if MySQL is installed in `E:\mysql` and the data directory is `D:\MySQLdata`, you can create the option file and set up a `[mysqld]` section to specify values for the `basedir` and `datadir` parameters:

      [mysqld]
      # set basedir to your installation path
      basedir=E:/mysql
      # set datadir to the location of your data directory
      datadir=D:/MySQLdata

  Note that Windows pathnames are specified in option files using (forward) slashes rather than backslashes. If you do use backslashes, you must double them:

      [mysqld]
      # set basedir to your installation path
      basedir=C:\\Program Files\\MySQL\\MySQL Server 5.0
      # set datadir to the location of your data directory
      datadir=D:\\MySQLdata

  MySQL Enterprise For expert advice on the start-up options appropriate to your circumstances, subscribe to the MySQL Network Monitoring and Advisory Service. For more information see, http://www.mysql.com/products/enterprise/advisors.html.

  If you change the `datadir` value in your MySQL configuration file, you must move the contents of the existing MySQL data directory before restarting the MySQL server.

  See Section 2.4.8.7, “Creating an Option File”.

- If you reinstall or upgrade MySQL without first stopping and removing the existing MySQL service and install MySQL using the MySQL Configuration Wizard, you may see this error:

      Error: Cannot create Windows service for MySql. Error: 0

  This occurs when the Configuration Wizard tries to install the service and finds an existing service with the same name.

  One solution to this problem is to choose a service name other than `mysql` when using the configuration wizard. This allows the new service to be installed correctly, but leaves the outdated service in place. Although this is harmless, it is best to remove old services that are no longer in use.

  To permanently remove the old `mysql` service, execute the following command as a user with administrative privileges, on the command-line:

      C:\> sc delete mysql
      [SC] DeleteService SUCCESS

  If the `sc` utility is not available for your version of Windows, download the `delsrv` utility from http://www.microsoft.com/windows2000/techinfo/reskit/tools/existing/delsrv-o.asp and use the `delsrv mysql` syntax.

#### 2.4.8.14. Upgrading MySQL on Windows

This section does not apply to MySQL Enterprise Server users.

This section lists some of the steps you should take when upgrading MySQL on Windows.

1. Review Section 2.4.16, “Upgrading MySQL”, for additional information on upgrading MySQL that is not specific to Windows.

2. You should always back up your current MySQL installation before performing an upgrade. See Section 5.10.1, “Database Backups”.

3. Download the latest Windows distribution of MySQL from http://dev.mysql.com/downloads/.

4. Before upgrading MySQL, you must stop the server. If the server is installed as a service, stop the service with the following command from the command prompt:

       C:\> NET STOP MySQL

   If you are not running the MySQL server as a service, use the following command to stop it:

       C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqladmin" -u root shutdown

   Note: If the MySQL `root` user account has a password, you need to invoke mysqladmin with the `-p` option and supply the password when prompted.

5. When upgrading to MySQL 5.0 from a version previous to 4.1.5, or when upgrading from a version of MySQL installed from a Zip archive to a version of MySQL installed with the MySQL Installation Wizard, you must manually remove the previous installation and MySQL service (if the server is installed as a service).

   To remove the MySQL service, use the following command:

       C:\> C:\mysql\bin\mysqld --remove

   If you do not remove the existing service, the MySQL Installation Wizard may fail to properly install the new MySQL service.

6. If you are using the MySQL Installation Wizard, start the wizard as described in Section 2.4.8.3, “Using the MySQL Installation Wizard”.

7. If you are installing MySQL from a Zip archive, extract the archive. You may either overwrite your existing MySQL installation (usually located at `C:\mysql`), or install it into a different directory, such as `C:\mysql5`. Overwriting the existing installation is recommended.

8. If you were running MySQL as a Windows service and you had to remove the service earlier in this procedure, reinstall the service. (See Section 2.4.8.11, “Starting MySQL as a Windows Service”.)

9. Restart the server. For example, use NET START MySQL if you run MySQL as a service, or invoke mysqld directly otherwise.

10. If you encounter errors, see Section 2.4.8.13, “Troubleshooting a MySQL Installation Under Windows”.

#### 2.4.8.15. MySQL on Windows Compared to MySQL on Unix

MySQL for Windows has proven itself to be very stable. The Windows version of MySQL has the same features as the corresponding Unix version, with the following exceptions:

- Windows 95 and threads

  Windows 95 leaks about 200 bytes of main memory for each thread creation. Each connection in MySQL creates a new thread, so you shouldn't run mysqld for an extended time on Windows 95 if your server handles many connections! Newer versions of Windows don't suffer from this bug.

- Limited number of ports

  Windows systems have about 4,000 ports available for client connections, and after a connection on a port closes, it takes two to four minutes before the port can be reused. In situations where clients connect to and disconnect from the server at a high rate, it is possible for all available ports to be used up before closed ports become available again. If this happens, the MySQL server appears to be unresponsive even though it is running. Note that ports may be used by other applications running on the machine as well, in which case the number of ports available to MySQL is lower.

  For more information about this problem, see http://support.microsoft.com/default.aspx?scid=kb;en-us;196271.

- Concurrent reads

  MySQL depends on the `pread()` and `pwrite()` system calls to be able to mix `INSERT` and `SELECT`. Currently, we use mutexes to emulate `pread()` and `pwrite()`. We intend to replace the file level interface with a virtual interface in the future so that we can use the `readfile()`/`writefile()` interface on NT, 2000, and XP to get more speed. The current implementation limits the number of open files that MySQL 5.0 can use to 2,048, which means that you cannot run as many concurrent threads on Windows NT, 2000, XP, and 2003 as on Unix.

- Blocking read

  MySQL uses a blocking read for each connection. That has the following implications if named-pipe connections are enabled:

  - A connection is not disconnected automatically after eight hours, as happens with the Unix version of MySQL.

  - If a connection hangs, it is not possible to break it without killing MySQL.

  - mysqladmin kill does not work on a sleeping connection.

  - mysqladmin shutdown cannot abort as long as there are sleeping connections.

  We plan to fix this problem in the future.

- `ALTER TABLE`

  While you are executing an `ALTER TABLE` statement, the table is locked from being used by other threads. This has to do with the fact that on Windows, you can't delete a file that is in use by another thread. In the future, we may find some way to work around this problem.

- `DROP TABLE`

  `DROP TABLE` on a table that is in use by a `MERGE` table does not work on Windows because the `MERGE` handler does the table mapping hidden from the upper layer of MySQL. Because Windows does not allow dropping files that are open, you first must flush all `MERGE` tables (with `FLUSH TABLES`) or drop the `MERGE` table before dropping the table.

- `DATA DIRECTORY` and `INDEX DIRECTORY`

  The `DATA DIRECTORY` and `INDEX DIRECTORY` options for `CREATE TABLE` are ignored on Windows, because Windows doesn't support symbolic links. These options also are ignored on systems that have a non-functional `realpath()` call.

- `DROP DATABASE`

  You cannot drop a database that is in use by some thread.

- Killing MySQL from the Task Manager

  On Windows 95, you cannot kill MySQL from the Task Manager or with the shutdown utility. You must stop it with mysqladmin shutdown.

- Case-insensitive names

  Filenames are not case sensitive on Windows, so MySQL database and table names are also not case sensitive on Windows. The only restriction is that database and table names must be specified using the same case throughout a given statement. See Section 9.2.2, “Identifier Case Sensitivity”.

- The ‘`\`’ pathname separator character

  Pathname components in Windows are separated by the ‘`\`’ character, which is also the escape character in MySQL. If you are using `LOAD DATA INFILE` or `SELECT ... INTO OUTFILE`, use Unix-style filenames with ‘`/`’ characters:

      mysql> LOAD DATA INFILE 'C:/tmp/skr.txt' INTO TABLE skr;
      mysql> SELECT * INTO OUTFILE 'C:/tmp/skr.txt' FROM skr;

  Alternatively, you must double the ‘`\`’ character:

      mysql> LOAD DATA INFILE 'C:\\tmp\\skr.txt' INTO TABLE skr;
      mysql> SELECT * INTO OUTFILE 'C:\\tmp\\skr.txt' FROM skr;

- Problems with pipes

  Pipes do not work reliably from the Windows command-line prompt. If the pipe includes the character `^Z` / `CHAR(24)`, Windows thinks that it has encountered end-of-file and aborts the program.

  This is mainly a problem when you try to apply a binary log as follows:

      C:\> mysqlbinlog binary_log_file | mysql --user=root

  If you have a problem applying the log and suspect that it is because of a `^Z` / `CHAR(24)` character, you can use the following workaround:

      C:\> mysqlbinlog binary_log_file --result-file=/tmp/bin.sql
      C:\> mysql --user=root --execute "source /tmp/bin.sql"

  The latter command also can be used to reliably read in any SQL file that may contain binary data.

- `Access denied for user` error

  If MySQL cannot resolve your hostname properly, you may get the following error when you attempt to run a MySQL client program to connect to a server running on the same machine:

      Access denied for user 'some_user'@'unknown'
      to database 'mysql'

  To fix this problem, you should create a file named `\windows\hosts` containing the following information:

      127.0.0.1       localhost

Here are some open issues for anyone who might want to help us improve MySQL on Windows:

- Add macros to use the faster thread-safe increment/decrement methods provided by Windows.

### 2.4.9. Installing MySQL on Linux

The recommended way to install MySQL on Linux is by using the RPM packages. The MySQL RPMs are currently built on a SuSE Linux 7.3 system, but should work on most versions of Linux that support rpm and use `glibc`. To obtain RPM packages, see Section 2.4.4, “How to Get MySQL”.

MySQL AB does provide some platform-specific RPMs; the difference between a platform-specific RPM and a generic RPM is that a platform-specific RPM is built on the targeted platform and is linked dynamically whereas a generic RPM is linked statically with LinuxThreads.

Note: RPM distributions of MySQL often are provided by other vendors. Be aware that they may differ in features and capabilities from those built by MySQL AB, and that the instructions in this manual do not necessarily apply to installing them. The vendor's instructions should be consulted instead.

If you have problems with an RPM file (for example, if you receive the error `Sorry, the host '`xxxx`' could not be looked up`), see Section 2.4.18.1.2, “Linux Binary Distribution Notes”.

In most cases, you need to install only the `MySQL-server` and `MySQL-client` packages to get a functional MySQL installation. The other packages are not required for a standard installation. If you want to run a MySQL-Max server that has additional capabilities, you should also install the `MySQL-Max` RPM. However, you should do so only after installing the `MySQL-server` RPM. See Section 5.3, “The mysqld-max Extended MySQL Server”.

If you get a dependency failure when trying to install MySQL packages (for example, `error: removing these packages would break dependencies: libmysqlclient.so.10 is needed by ...`), you should also install the `MySQL-shared-compat` package, which includes both the shared libraries for backward compatibility (`libmysqlclient.so.12` for MySQL 4.0 and `libmysqlclient.so.10` for MySQL 3.23).

Some Linux distributions still ship with MySQL 3.23 and they usually link applications dynamically to save disk space. If these shared libraries are in a separate package (for example, `MySQL-shared`), it is sufficient to simply leave this package installed and just upgrade the MySQL server and client packages (which are statically linked and do not depend on the shared libraries). For distributions that include the shared libraries in the same package as the MySQL server (for example, Red Hat Linux), you could either install our 3.23 `MySQL-shared` RPM, or use the `MySQL-shared-compat` package instead. (Do not install both.)

The following RPM packages are available:

- `MySQL-server-`VERSION`.i386.rpm`

  The MySQL server. You need this unless you only want to connect to a MySQL server running on another machine.

  Note: Server RPM files were called `MySQL-`VERSION`.i386.rpm` before MySQL 4.0.10. That is, they did not have `-server` in the name.

- `MySQL-Max-`VERSION`.i386.rpm`

  The MySQL-Max server. This server has additional capabilities that the one provided in the `MySQL-server` RPM does not. You must install the `MySQL-server` RPM first, because the `MySQL-Max` RPM depends on it.

- `MySQL-client-`VERSION`.i386.rpm`

  The standard MySQL client programs. You probably always want to install this package.

- `MySQL-bench-`VERSION`.i386.rpm`

  Tests and benchmarks. Requires Perl and the `DBI` and `DBD::mysql` modules.

- `MySQL-devel-`VERSION`.i386.rpm`

  The libraries and include files that are needed if you want to compile other MySQL clients, such as the Perl modules.

- `MySQL-shared-`VERSION`.i386.rpm`

  This package contains the shared libraries (`libmysqlclient.so*`) that certain languages and applications need to dynamically load and use MySQL. It contains single-threaded and thread-safe libraries. If you install this package, do not install the `MySQL-shared-compat` package.

- `MySQL-shared-compat-`VERSION`.i386.rpm`

  This package includes the shared libraries for MySQL 3.23, 4.0, 4.1, and 5.0. It contains single-threaded and thread-safe libraries. Install this package instead of `MySQL-shared` if you have applications installed that are dynamically linked against older versions of MySQL but you want to upgrade to the current version without breaking the library dependencies.

- `MySQL-embedded-`VERSION`.i386.rpm`

  The embedded MySQL server library (available as of MySQL 4.0).

- `MySQL-`VERSION`.src.rpm`

  This contains the source code for all of the previous packages. It can also be used to rebuild the RPMs on other architectures (for example, Alpha or SPARC).

To see all files in an RPM package (for example, a `MySQL-server` RPM), run a command like this:

    shell> rpm -qpl MySQL-server-VERSION.i386.rpm

To perform a standard minimal installation, install the server and client RPMs:

    shell> rpm -i MySQL-server-VERSION.i386.rpm
    shell> rpm -i MySQL-client-VERSION.i386.rpm

To install only the client programs, install just the client RPM:

    shell> rpm -i MySQL-client-VERSION.i386.rpm

RPM provides a feature to verify the integrity and authenticity of packages before installing them. If you would like to learn more about this feature, see Section 2.4.5, “Verifying Package Integrity Using MD5 Checksums or `GnuPG`”.

The server RPM places data under the `/var/lib/mysql` directory. The RPM also creates a login account for a user named `mysql` (if one does not exist) to use for running the MySQL server, and creates the appropriate entries in `/etc/init.d/` to start the server automatically at boot time. (This means that if you have performed a previous installation and have made changes to its startup script, you may want to make a copy of the script so that you don't lose it when you install a newer RPM.) See Section 2.4.15.2.2, “Starting and Stopping MySQL Automatically”, for more information on how MySQL can be started automatically on system startup.

If you want to install the MySQL RPM on older Linux distributions that do not support initialization scripts in `/etc/init.d` (directly or via a symlink), you should create a symbolic link that points to the location where your initialization scripts actually are installed. For example, if that location is `/etc/rc.d/init.d`, use these commands before installing the RPM to create `/etc/init.d` as a symbolic link that points there:

    shell> cd /etc
    shell> ln -s rc.d/init.d .

However, all current major Linux distributions should support the new directory layout that uses `/etc/init.d`, because it is required for LSB (Linux Standard Base) compliance.

If the RPM files that you install include `MySQL-server`, the mysqld server should be up and running after installation. You should be able to start using MySQL.

If something goes wrong, you can find more information in the binary installation section. See Section 2.4.13, “Installing MySQL on Other Unix-Like Systems”.

Note: The accounts that are listed in the MySQL grant tables initially have no passwords. After starting the server, you should set up passwords for them using the instructions in Section 2.4.15, “Post-Installation Setup and Testing”.

### 2.4.10. Installing MySQL on Mac OS X

You can install MySQL on Mac OS X 10.3.x (“Panther”) or newer using a Mac OS X binary package in PKG format instead of the binary tarball distribution. Please note that older versions of Mac OS X (for example, 10.1.x or 10.2.x) are not supported by this package.

The package is located inside a disk image (`.dmg`) file that you first need to mount by double-clicking its icon in the Finder. It should then mount the image and display its contents.

To obtain MySQL, see Section 2.4.4, “How to Get MySQL”.

Note: Before proceeding with the installation, be sure to shut down all running MySQL server instances by either using the MySQL Manager Application (on Mac OS X Server) or via mysqladmin shutdown on the command line.

To actually install the MySQL PKG file, double-click on the package icon. This launches the Mac OS X Package Installer, which guides you through the installation of MySQL.

Due to a bug in the Mac OS X package installer, you may see this error message in the destination disk selection dialog:

    You cannot install this software on this disk. (null)

If this error occurs, simply click the `Go Back` button once to return to the previous screen. Then click `Continue` to advance to the destination disk selection again, and you should be able to choose the destination disk correctly. We have reported this bug to Apple and it is investigating this problem.

The Mac OS X PKG of MySQL installs itself into `/usr/local/mysql-`VERSION`` and also installs a symbolic link, `/usr/local/mysql`, that points to the new location. If a directory named `/usr/local/mysql` exists, it is renamed to `/usr/local/mysql.bak` first. Additionally, the installer creates the grant tables in the `mysql` database by executing mysql_install_db.

The installation layout is similar to that of a tar file binary distribution; all MySQL binaries are located in the directory `/usr/local/mysql/bin`. The MySQL socket file is created as `/tmp/mysql.sock` by default. See Section 2.4.6, “Installation Layouts”.

MySQL installation requires a Mac OS X user account named `mysql`. A user account with this name should exist by default on Mac OS X 10.2 and up.

If you are running Mac OS X Server, a version of MySQL should already be installed. The following table shows the versions of MySQL that ship with Mac OS X Server versions.

Mac OS X Server Version | MySQL Version
10.2-10.2.2 | 3.23.51
10.2.3-10.2.6 | 3.23.53
10.3 | 4.0.14
10.3.2 | 4.0.16
10.4.0 | 4.1.10a

This manual section covers the installation of the official MySQL Mac OS X PKG only. Make sure to read Apple's help information about installing MySQL: Run the “Help View” application, select “Mac OS X Server” help, do a search for “MySQL,” and read the item entitled “Installing MySQL.”

For preinstalled versions of MySQL on Mac OS X Server, note especially that you should start mysqld with safe_mysqld instead of mysqld_safe if MySQL is older than version 4.0.

If you previously used Marc Liyanage's MySQL packages for Mac OS X from http://www.entropy.ch, you can simply follow the update instructions for packages using the binary installation layout as given on his pages.

If you are upgrading from Marc's 3.23.x versions or from the Mac OS X Server version of MySQL to the official MySQL PKG, you also need to convert the existing MySQL privilege tables to the current format, because some new security privileges have been added. See Section 5.6.3, “mysql_upgrade — Check Tables for MySQL Upgrade”.

If you want MySQL to start automatically during system startup, you also need to install the MySQL Startup Item. It is part of the Mac OS X installation disk images as a separate installation package. Simply double-click the MySQLStartupItem.pkg icon and follow the instructions to install it. The Startup Item need be installed only once. There is no need to install it each time you upgrade the MySQL package later.

The Startup Item for MySQL is installed into `/Library/StartupItems/MySQLCOM`. (Before MySQL 4.1.2, the location was `/Library/StartupItems/MySQL`, but that collided with the MySQL Startup Item installed by Mac OS X Server.) Startup Item installation adds a variable `MYSQLCOM=-YES-` to the system configuration file `/etc/hostconfig`. If you want to disable the automatic startup of MySQL, simply change this variable to `MYSQLCOM=-NO-`.

On Mac OS X Server, the default MySQL installation uses the variable `MYSQL` in the `/etc/hostconfig` file. The MySQL AB Startup Item installer disables this variable by setting it to `MYSQL=-NO-`. This avoids boot time conflicts with the `MYSQLCOM` variable used by the MySQL AB Startup Item. However, it does not shut down a running MySQL server. You should do that yourself.

After the installation, you can start up MySQL by running the following commands in a terminal window. You must have administrator privileges to perform this task.

If you have installed the Startup Item, use this command:

    shell> sudo /Library/StartupItems/MySQLCOM/MySQLCOM start
    (Enter your password, if necessary)
    (Press Control-D or enter "exit" to exit the shell)

If you don't use the Startup Item, enter the following command sequence:

    shell> cd /usr/local/mysql
    shell> sudo ./bin/mysqld_safe
    (Enter your password, if necessary)
    (Press Control-Z)
    shell> bg
    (Press Control-D or enter "exit" to exit the shell)

You should be able to connect to the MySQL server, for example, by running `/usr/local/mysql/bin/mysql`.

Note: The accounts that are listed in the MySQL grant tables initially have no passwords. After starting the server, you should set up passwords for them using the instructions in Section 2.4.15, “Post-Installation Setup and Testing”.

You might want to add aliases to your shell's resource file to make it easier to access commonly used programs such as mysql and mysqladmin from the command line. The syntax for bash is:

    alias mysql=/usr/local/mysql/bin/mysql
    alias mysqladmin=/usr/local/mysql/bin/mysqladmin

For tcsh, use:

    alias mysql /usr/local/mysql/bin/mysql
    alias mysqladmin /usr/local/mysql/bin/mysqladmin

Even better, add `/usr/local/mysql/bin` to your `PATH` environment variable. For example, add the following line to your `$HOME/.bashrc` file if your shell is bash:

    PATH=${PATH}:/usr/local/mysql/bin

Add the following line to your `$HOME/.tcshrc` file if your shell is tcsh:

    setenv PATH ${PATH}:/usr/local/mysql/bin

If no `.bashrc` or `.tcshrc` file exists in your home directory, create it with a text editor.

If you are upgrading an existing installation, note that installing a new MySQL PKG does not remove the directory of an older installation. Unfortunately, the Mac OS X Installer does not yet offer the functionality required to properly upgrade previously installed packages.

To use your existing databases with the new installation, you'll need to copy the contents of the old data directory to the new data directory. Make sure that neither the old server nor the new one is running when you do this. After you have copied over the MySQL database files from the previous installation and have successfully started the new server, you should consider removing the old installation files to save disk space. Additionally, you should also remove older versions of the Package Receipt directories located in `/Library/Receipts/mysql-`VERSION`.pkg`.

### 2.4.11. Installing MySQL on Solaris

If you install MySQL using a binary tarball distribution on Solaris, you may run into trouble even before you get the MySQL distribution unpacked, as the Solaris tar cannot handle long filenames. This means that you may see errors when you try to unpack MySQL.

If this occurs, you must use GNU tar (gtar) to unpack the distribution. You can find a precompiled copy for Solaris at http://dev.mysql.com/downloads/os-solaris.html.

You can install MySQL on Solaris using a binary package in PKG format instead of the binary tarball distribution. Before installing using the binary PKG format, you should create the `mysql` user and group, for example:

    groupadd mysql
    useradd -g mysql mysql

Some basic PKG-handling commands follow:

- To add a package:

      pkgadd -d package_name.pkg

- To remove a package:

      pkgrm package_name

- To get a full list of installed packages:

      pkginfo

- To get detailed information for a package:

      pkginfo -l package_name

- To list the files belonging to a package:

      pkgchk -v package_name

- To get packaging information for an arbitrary file:

      pkgchk -l -p file_name

For additional information about installing MySQL on Solaris, see Section 2.4.18.3, “Solaris Notes”.

### 2.4.12. Installing MySQL on NetWare

This section does not apply to MySQL Enterprise Server users.

Porting MySQL to NetWare was an effort spearheaded by Novell. Novell customers should be pleased to note that NetWare 6.5 ships with bundled MySQL binaries, complete with an automatic commercial use license for all servers running that version of NetWare.

MySQL for NetWare is compiled using a combination of Metrowerks CodeWarrior for NetWare and special cross-compilation versions of the GNU autotools.

The latest binary packages for NetWare can be obtained at http://dev.mysql.com/downloads/. See Section 2.4.4, “How to Get MySQL”.

To host MySQL, the NetWare server must meet these requirements:

- The latest Support Pack of NetWare 6.5 must be installed.

- The system must meet Novell's minimum requirements to run the respective version of NetWare.

- MySQL data and the program binaries must be installed on an NSS volume; traditional volumes are not supported.

To install MySQL for NetWare, use the following procedure:

1. If you are upgrading from a prior installation, stop the MySQL server. This is done from the server console, using the following command:

       SERVER:  mysqladmin -u root shutdown

   Note: If the MySQL `root` user account has a password, you need to invoke mysqladmin with the `-p` option and supply the password when prompted.

2. Log on to the target server from a client machine with access to the location where you are installing MySQL.

3. Extract the binary package Zip file onto the server. Be sure to allow the paths in the Zip file to be used. It is safe to simply extract the file to `SYS:\`.

   If you are upgrading from a prior installation, you may need to copy the data directory (for example, `SYS:MYSQL\DATA`), as well as `my.cnf`, if you have customized it. You can then delete the old copy of MySQL.

4. You might want to rename the directory to something more consistent and easy to use. The examples in this manual use `SYS:MYSQL` to refer to the installation directory.

   Note that MySQL installation on NetWare does not detect if a version of MySQL is already installed outside the NetWare release. Therefore, if you have installed the latest MySQL version from the Web (for example, MySQL 4.1 or later) in `SYS:\MYSQL`, you must rename the folder before upgrading the NetWare server; otherwise, files in `SYS:\MySQL` are overwritten by the MySQL version present in NetWare Support Pack.

5. At the server console, add a search path for the directory containing the MySQL NLMs. For example:

       SERVER:  SEARCH ADD SYS:MYSQL\BIN

6. Initialize the data directory and the grant tables, if necessary, by executing mysql_install_db at the server console.

7. Start the MySQL server using mysqld_safe at the server console.

8. To finish the installation, you should also add the following commands to `autoexec.ncf`. For example, if your MySQL installation is in `SYS:MYSQL` and you want MySQL to start automatically, you could add these lines:

       #Starts the MySQL 5.0.x database server
       SEARCH ADD SYS:MYSQL\BIN
       MYSQLD_SAFE

   If you are running MySQL on NetWare 6.0, we strongly suggest that you use the `--skip-external-locking` option on the command line:

       #Starts the MySQL 5.0.x database server
       SEARCH ADD SYS:MYSQL\BIN
       MYSQLD_SAFE --skip-external-locking

   It is also necessary to use `CHECK TABLE` and `REPAIR TABLE` instead of myisamchk, because myisamchk makes use of external locking. External locking is known to have problems on NetWare 6.0; the problem has been eliminated in NetWare 6.5. Note that the use of MySQL on Netware 6.0 is not officially supported.

   mysqld_safe on NetWare provides a screen presence. When you unload (shut down) the mysqld_safe NLM, the screen does not go away by default. Instead, it prompts for user input:

       *<NLM has terminated; Press any key to close the screen>*

   If you want NetWare to close the screen automatically instead, use the `--autoclose` option to mysqld_safe. For example:

       #Starts the MySQL 5.0.x database server
       SEARCH ADD SYS:MYSQL\BIN
       MYSQLD_SAFE --autoclose

   The behavior of mysqld_safe on NetWare is described further in Section 5.4.1, “mysqld_safe — MySQL Server Startup Script”.

9. When installing MySQL, either for the first time or upgrading from a previous version, download and install the latest and appropriate Perl module and PHP extensions for NetWare:

   - Perl: http://forge.novell.com/modules/xfcontent/downloads.php/perl/Modules/

   - PHP: http://forge.novell.com/modules/xfcontent/downloads.php/php/Modules/

If there was an existing installation of MySQL on the NetWare server, be sure to check for existing MySQL startup commands in `autoexec.ncf`, and edit or delete them as necessary.

Note: The accounts that are listed in the MySQL grant tables initially have no passwords. After starting the server, you should set up passwords for them using the instructions in Section 2.4.15, “Post-Installation Setup and Testing”.

### 2.4.13. Installing MySQL on Other Unix-Like Systems

This section does not apply to MySQL Enterprise Server users.

This section covers the installation of MySQL binary distributions that are provided for various platforms in the form of compressed tar files (files with a `.tar.gz` extension). See Section 2.4.3.5, “MySQL Binaries Compiled by MySQL AB”, for a detailed list.

To obtain MySQL, see Section 2.4.4, “How to Get MySQL”.

MySQL tar file binary distributions have names of the form `mysql-`VERSION`-`OS`.tar.gz`, where ``VERSION`` is a number (for example, `5.0.34`), and `OS` indicates the type of operating system for which the distribution is intended (for example, `pc-linux-i686`).

In addition to these generic packages, we also offer binaries in platform-specific package formats for selected platforms. See Section 2.4.7, “Standard MySQL Installation Using a Binary Distribution”, for more information on how to install these.

You need the following tools to install a MySQL tar file binary distribution:

- GNU `gunzip` to uncompress the distribution.

- A reasonable tar to unpack the distribution. GNU tar is known to work. Some operating systems come with a preinstalled version of tar that is known to have problems. For example, Mac OS X tar and Sun tar are known to have problems with long filenames. On Mac OS X, you can use the preinstalled gnutar program. On other systems with a deficient tar, you should install GNU tar first.

If you run into problems and need to file a bug report, please use the instructions in Section 1.8, “How to Report Bugs or Problems”.

The basic commands that you must execute to install and use a MySQL binary distribution are:

    shell> groupadd mysql
    shell> useradd -g mysql mysql
    shell> cd /usr/local
    shell> gunzip < /path/to/mysql-VERSION-OS.tar.gz | tar xvf -
    shell> ln -s full-path-to-mysql-VERSION-OS mysql
    shell> cd mysql
    shell> scripts/mysql_install_db --user=mysql
    shell> chown -R root  .
    shell> chown -R mysql data
    shell> chgrp -R mysql .
    shell> bin/mysqld_safe --user=mysql &

Note: This procedure does not set up any passwords for MySQL accounts. After following the procedure, proceed to Section 2.4.15, “Post-Installation Setup and Testing”.

A more detailed version of the preceding description for installing a binary distribution follows:

1. Add a login user and group for mysqld to run as:

       shell> groupadd mysql
       shell> useradd -g mysql mysql

   These commands add the `mysql` group and the `mysql` user. The syntax for useradd and groupadd may differ slightly on different versions of Unix, or they may have different names such as adduser and addgroup.

   You might want to call the user and group something else instead of `mysql`. If so, substitute the appropriate name in the following steps.

2. Pick the directory under which you want to unpack the distribution and change location into it. In the following example, we unpack the distribution under `/usr/local`. (The instructions, therefore, assume that you have permission to create files and directories in `/usr/local`. If that directory is protected, you must perform the installation as `root`.)

       shell> cd /usr/local

3. Obtain a distribution file using the instructions in Section 2.4.4, “How to Get MySQL”. For a given release, binary distributions for all platforms are built from the same MySQL source distribution.

4. Unpack the distribution, which creates the installation directory. Then create a symbolic link to that directory:

       shell> gunzip < /path/to/mysql-VERSION-OS.tar.gz | tar xvf -
       shell> ln -s full-path-to-mysql-VERSION-OS mysql

   The tar command creates a directory named `mysql-`VERSION`-`OS``. The `ln` command makes a symbolic link to that directory. This lets you refer more easily to the installation directory as `/usr/local/mysql`.

   With GNU tar, no separate invocation of `gunzip` is necessary. You can replace the first line with the following alternative command to uncompress and extract the distribution:

       shell> tar zxvf /path/to/mysql-VERSION-OS.tar.gz

5. Change location into the installation directory:

       shell> cd mysql

   You will find several files and subdirectories in the `mysql` directory. The most important for installation purposes are the `bin` and `scripts` subdirectories:

   - The `bin` directory contains client programs and the server. You should add the full pathname of this directory to your `PATH` environment variable so that your shell finds the MySQL programs properly. See Appendix I, Environment Variables.

   - The `scripts` directory contains the mysql_install_db script used to initialize the `mysql` database containing the grant tables that store the server access permissions.

6. If you have not installed MySQL before, you must create the MySQL grant tables:

       shell> scripts/mysql_install_db --user=mysql

   If you run the command as `root`, you must use the `--user` option as shown. The value of the option should be the name of the login account that you created in the first step to use for running the server. If you run the command while logged in as that user, you can omit the `--user` option.

   After creating or updating the grant tables, you need to restart the server manually.

7. Change the ownership of program binaries to `root` and ownership of the data directory to the user that you run mysqld as. Assuming that you are located in the installation directory (`/usr/local/mysql`), the commands look like this:

       shell> chown -R root  .
       shell> chown -R mysql data
       shell> chgrp -R mysql .

   The first command changes the owner attribute of the files to the `root` user. The second changes the owner attribute of the data directory to the `mysql` user. The third changes the group attribute to the `mysql` group.

8. If you want MySQL to start automatically when you boot your machine, you can copy `support-files/mysql.server` to the location where your system has its startup files. More information can be found in the `support-files/mysql.server` script itself and in Section 2.4.15.2.2, “Starting and Stopping MySQL Automatically”.

9. You can set up new accounts using the bin/mysql_setpermission script if you install the `DBI` and `DBD::mysql` Perl modules. For instructions, see Section 2.4.19, “Perl Installation Notes”.

10. If you would like to use mysqlaccess and have the MySQL distribution in some non-standard location, you must change the location where mysqlaccess expects to find the mysql client. Edit the `bin/mysqlaccess` script at approximately line 18. Search for a line that looks like this:

        $MYSQL     = '/usr/local/bin/mysql';    # path to mysql executable

    Change the path to reflect the location where mysql actually is stored on your system. If you do not do this, a `Broken pipe` error will occur when you run mysqlaccess.

After everything has been unpacked and installed, you should test your distribution. To start the MySQL server, use the following command:

    shell> bin/mysqld_safe --user=mysql &

If that command fails immediately and prints `mysqld ended`, you can find some information in the ``host_name`.err` file in the data directory.

More information about mysqld_safe is given in Section 5.4.1, “mysqld_safe — MySQL Server Startup Script”.

Note: The accounts that are listed in the MySQL grant tables initially have no passwords. After starting the server, you should set up passwords for them using the instructions in Section 2.4.15, “Post-Installation Setup and Testing”.

### 2.4.14. MySQL Installation Using a Source Distribution

This section does not apply to MySQL Enterprise Server users.

Before you proceed with an installation from source, first check whether our binary is available for your platform and whether it works for you. We put a great deal of effort into ensuring that our binaries are built with the best possible options.

To obtain a source distribution for MySQL, Section 2.4.4, “How to Get MySQL”.

MySQL source distributions are provided as compressed tar archives and have names of the form `mysql-`VERSION`.tar.gz`, where `VERSION` is a number like `5.0.34`.

You need the following tools to build and install MySQL from source:

- GNU `gunzip` to uncompress the distribution.

- A reasonable tar to unpack the distribution. GNU tar is known to work. Some operating systems come with a preinstalled version of tar that is known to have problems. For example, the tar provided with early versions of Mac OS X tar, SunOS 4.x and Solaris 8 and earlier are known to have problems with long filenames. On Mac OS X, you can use the preinstalled gnutar program. On other systems with a deficient tar, you should install GNU tar first.

- A working ANSI C++ compiler. gcc 2.95.2 or later, egcs 1.0.2 or later or egcs 2.91.66, SGI C++, and SunPro C++ are some of the compilers that are known to work. `libg++` is not needed when using gcc. gcc 2.7.x has a bug that makes it impossible to compile some perfectly legal C++ files, such as `sql/sql_base.cc`. If you have only gcc 2.7.x, you must upgrade your gcc to be able to compile MySQL. gcc 2.8.1 is also known to have problems on some platforms, so it should be avoided if a new compiler exists for the platform.

  gcc 2.95.2 or later is recommended when compiling MySQL 3.23.x.

- A good make program. GNU make is always recommended and is sometimes required. If you have problems, we recommend GNU make 3.75 or newer.

If you are using a version of gcc recent enough to understand the `-fno-exceptions` option, it is very important that you use this option. Otherwise, you may compile a binary that crashes randomly. We also recommend that you use `-felide-constructors` and `-fno-rtti` along with `-fno-exceptions`. When in doubt, do the following:

    CFLAGS="-O3" CXX=gcc CXXFLAGS="-O3 -felide-constructors \
           -fno-exceptions -fno-rtti" ./configure \
           --prefix=/usr/local/mysql --enable-assembler \
           --with-mysqld-ldflags=-all-static

On most systems, this gives you a fast and stable binary.

If you run into problems and need to file a bug report, please use the instructions in Section 1.8, “How to Report Bugs or Problems”.

#### 2.4.14.1. Source Installation Overview

This section does not apply to MySQL Enterprise Server users.

The basic commands that you must execute to install a MySQL source distribution are:

    shell> groupadd mysql
    shell> useradd -g mysql mysql
    shell> gunzip < mysql-VERSION.tar.gz | tar -xvf -
    shell> cd mysql-VERSION
    shell> ./configure --prefix=/usr/local/mysql
    shell> make
    shell> make install
    shell> cp support-files/my-medium.cnf /etc/my.cnf
    shell> cd /usr/local/mysql
    shell> bin/mysql_install_db --user=mysql
    shell> chown -R root  .
    shell> chown -R mysql var
    shell> chgrp -R mysql .
    shell> bin/mysqld_safe --user=mysql &

If you start from a source RPM, do the following:

    shell> rpmbuild --rebuild --clean MySQL-VERSION.src.rpm

This makes a binary RPM that you can install. For older versions of RPM, you may have to replace the command rpmbuild with rpm instead.

Note: This procedure does not set up any passwords for MySQL accounts. After following the procedure, proceed to Section 2.4.15, “Post-Installation Setup and Testing”, for post-installation setup and testing.

A more detailed version of the preceding description for installing MySQL from a source distribution follows:

1. Add a login user and group for mysqld to run as:

       shell> groupadd mysql
       shell> useradd -g mysql mysql

   These commands add the `mysql` group and the `mysql` user. The syntax for useradd and groupadd may differ slightly on different versions of Unix, or they may have different names such as adduser and addgroup.

   You might want to call the user and group something else instead of `mysql`. If so, substitute the appropriate name in the following steps.

2. Pick the directory under which you want to unpack the distribution and change location into it.

3. Obtain a distribution file using the instructions in Section 2.4.4, “How to Get MySQL”.

4. Unpack the distribution into the current directory:

       shell> gunzip < /path/to/mysql-VERSION.tar.gz | tar xvf -

   This command creates a directory named `mysql-`VERSION``.

   With GNU tar, no separate invocation of `gunzip` is necessary. You can use the following alternative command to uncompress and extract the distribution:

       shell> tar zxvf /path/to/mysql-VERSION-OS.tar.gz

5. Change location into the top-level directory of the unpacked distribution:

       shell> cd mysql-VERSION

   Note that currently you must configure and build MySQL from this top-level directory. You cannot build it in a different directory.

6. Configure the release and compile everything:

       shell> ./configure --prefix=/usr/local/mysql
       shell> make

   When you run configure, you might want to specify other options. Run ./configure --help for a list of options. Section 2.4.14.2, “Typical configure Options”, discusses some of the more useful options.

   If configure fails and you are going to send mail to a MySQL mailing list to ask for assistance, please include any lines from `config.log` that you think can help solve the problem. Also include the last couple of lines of output from configure. To file a bug report, please use the instructions in Section 1.8, “How to Report Bugs or Problems”.

   If the compile fails, see Section 2.4.14.4, “Dealing with Problems Compiling MySQL”, for help.

7. Install the distribution:

       shell> make install

   If you want to set up an option file, use one of those present in the `support-files` directory as a template. For example:

       shell> cp support-files/my-medium.cnf /etc/my.cnf

   You might need to run these commands as `root`.

   If you want to configure support for `InnoDB` tables, you should edit the `/etc/my.cnf` file, remove the `#` character before the option lines that start with `innodb_...`, and modify the option values to be what you want. See Section 4.3.2, “Using Option Files”, and Section 14.2.3, “`InnoDB` Configuration”.

8. Change location into the installation directory:

       shell> cd /usr/local/mysql

9. If you haven't installed MySQL before, you must create the MySQL grant tables:

       shell> bin/mysql_install_db --user=mysql

   If you run the command as `root`, you should use the `--user` option as shown. The value of the option should be the name of the login account that you created in the first step to use for running the server. If you run the command while logged in as that user, you can omit the `--user` option.

   After using mysql_install_db to create the grant tables for MySQL, you must restart the server manually. The mysqld_safe command to do this is shown in a later step.

10. Change the ownership of program binaries to `root` and ownership of the data directory to the user that you run mysqld as. Assuming that you are located in the installation directory (`/usr/local/mysql`), the commands look like this:

        shell> chown -R root  .
        shell> chown -R mysql var
        shell> chgrp -R mysql .

    The first command changes the owner attribute of the files to the `root` user. The second changes the owner attribute of the data directory to the `mysql` user. The third changes the group attribute to the `mysql` group.

11. If you want MySQL to start automatically when you boot your machine, you can copy `support-files/mysql.server` to the location where your system has its startup files. More information can be found in the `support-files/mysql.server` script itself; see also Section 2.4.15.2.2, “Starting and Stopping MySQL Automatically”.

12. You can set up new accounts using the bin/mysql_setpermission script if you install the `DBI` and `DBD::mysql` Perl modules. For instructions, see Section 2.4.19, “Perl Installation Notes”.

After everything has been installed, you should test your distribution. To start the MySQL server, use the following command:

    shell> /usr/local/mysql/bin/mysqld_safe --user=mysql &

If that command fails immediately and prints `mysqld ended`, you can find some information in the ``host_name`.err` file in the data directory.

More information about mysqld_safe is given in Section 5.4.1, “mysqld_safe — MySQL Server Startup Script”.

Note: The accounts that are listed in the MySQL grant tables initially have no passwords. After starting the server, you should set up passwords for them using the instructions in Section 2.4.15, “Post-Installation Setup and Testing”.

#### 2.4.14.2. Typical configure Options

This section does not apply to MySQL Enterprise Server users.

The configure script gives you a great deal of control over how you configure a MySQL source distribution. Typically you do this using options on the configure command line. You can also affect configure using certain environment variables. See Appendix I, Environment Variables. For a full list of options supported by configure, run this command:

    shell> ./configure --help

Some of the configure options available are described here:

- To compile just the MySQL client libraries and client programs and not the server, use the `--without-server` option:

      shell> ./configure --without-server

  If you have no C++ compiler, some client programs such as mysql cannot be compiled because they require C++.. In this case, you can remove the code in configure that tests for the C++ compiler and then run ./configure with the `--without-server` option. The compile step should still try to build all clients, but you can ignore any warnings about files such as `mysql.cc`. (If make stops, try make -k to tell it to continue with the rest of the build even if errors occur.)

- If you want to build the embedded MySQL library (`libmysqld.a`), use the `--with-embedded-server` option.

- If you don't want your log files and database directories located under `/usr/local/var`, use a configure command something like one of these:

      shell> ./configure --prefix=/usr/local/mysql
      shell> ./configure --prefix=/usr/local \
                 --localstatedir=/usr/local/mysql/data

  The first command changes the installation prefix so that everything is installed under `/usr/local/mysql` rather than the default of `/usr/local`. The second command preserves the default installation prefix, but overrides the default location for database directories (normally `/usr/local/var`) and changes it to `/usr/local/mysql/data`.

  You can also specify the installation directory and data directory locations at server startup time by using the `--basedir` and `--datadir` options. These can be given on the command line or in an MySQL option file, although it is more common to use an option file. See Section 4.3.2, “Using Option Files”.

- If you are using Unix and you want the MySQL socket file location to be somewhere other than the default location (normally in the directory `/tmp` or `/var/run`), use a configure command like this:

      shell> ./configure \
                 --with-unix-socket-path=/usr/local/mysql/tmp/mysql.sock

  The socket filename must be an absolute pathname. You can also change the location of `mysql.sock` at server startup by using a MySQL option file. See Section B.4.5, “How to Protect or Change the MySQL Unix Socket File”.

- If you want to compile statically linked programs (for example, to make a binary distribution, to get better performance, or to work around problems with some Red Hat Linux distributions), run configure like this:

      shell> ./configure --with-client-ldflags=-all-static \
                 --with-mysqld-ldflags=-all-static

- If you are using gcc and don't have `libg++` or `libstdc++` installed, you can tell configure to use gcc as your C++ compiler:

      shell> CC=gcc CXX=gcc ./configure

  When you use gcc as your C++ compiler, it does not attempt to link in `libg++` or `libstdc++`. This may be a good thing to do even if you have those libraries installed. Some versions of them have caused strange problems for MySQL users in the past.

  The following list indicates some compilers and environment variable settings that are commonly used with each one.

  - gcc 2.7.2:

        CC=gcc CXX=gcc CXXFLAGS="-O3 -felide-constructors"

  - egcs 1.0.3a:

        CC=gcc CXX=gcc CXXFLAGS="-O3 -felide-constructors \
        -fno-exceptions -fno-rtti"

  - gcc 2.95.2:

        CFLAGS="-O3 -mpentiumpro" CXX=gcc CXXFLAGS="-O3 -mpentiumpro \
        -felide-constructors -fno-exceptions -fno-rtti"

  - `pgcc` 2.90.29 or newer:

        CFLAGS="-O3 -mpentiumpro -mstack-align-double" CXX=gcc \
        CXXFLAGS="-O3 -mpentiumpro -mstack-align-double \
        -felide-constructors -fno-exceptions -fno-rtti"

  In most cases, you can get a reasonably optimized MySQL binary by using the options from the preceding list and adding the following options to the configure line:

      --prefix=/usr/local/mysql --enable-assembler \
      --with-mysqld-ldflags=-all-static

  The full configure line would, in other words, be something like the following for all recent gcc versions:

      CFLAGS="-O3 -mpentiumpro" CXX=gcc CXXFLAGS="-O3 -mpentiumpro \
      -felide-constructors -fno-exceptions -fno-rtti" ./configure \
      --prefix=/usr/local/mysql --enable-assembler \
      --with-mysqld-ldflags=-all-static

  The binaries we provide on the MySQL Web site at http://dev.mysql.com/downloads/ are all compiled with full optimization and should be perfect for most users. See Section 2.4.3.5, “MySQL Binaries Compiled by MySQL AB”. There are some configuration settings you can tweak to build an even faster binary, but these are only for advanced users. See Section 7.5.4, “How Compiling and Linking Affects the Speed of MySQL”.

  If the build fails and produces errors about your compiler or linker not being able to create the shared library `libmysqlclient.so.`N`` (where `N` is a version number), you can work around this problem by giving the `--disable-shared` option to configure. In this case, configure does not build a shared `libmysqlclient.so.`N`` library.

- By default, MySQL uses the `latin1` (cp1252 West European) character set. To change the default set, use the `--with-charset` option:

      shell> ./configure --with-charset=CHARSET

  `CHARSET` may be one of `binary`, `armscii8`, `ascii`, `big5`, `cp1250`, `cp1251`, `cp1256`, `cp1257`, `cp850`, `cp852`, `cp866`, `cp932`, `dec8`, `eucjpms`, `euckr`, `gb2312`, `gbk`, `geostd8`, `greek`, `hebrew`, `hp8`, `keybcs2`, `koi8r`, `koi8u`, `latin1`, `latin2`, `latin5`, `latin7`, `macce`, `macroman`, `sjis`, `swe7`, `tis620`, `ucs2`, `ujis`, `utf8`. See Section 5.11.1, “The Character Set Used for Data and Sorting”. (Additional character sets might be available. Check the output from ./configure --help for the current list.)

  The default collation may also be specified. MySQL uses the `latin1_swedish_ci` collation by default. To change this, use the `--with-collation` option:

      shell> ./configure --with-collation=COLLATION

  To change both the character set and the collation, use both the `--with-charset` and `--with-collation` options. The collation must be a legal collation for the character set. (Use the `SHOW COLLATION` statement to determine which collations are available for each character set.)

  Warning: If you change character sets after having created any tables, you must run myisamchk -r -q --set-collation=`collation_name` on every `MyISAM` table. Your indexes may be sorted incorrectly otherwise. This can happen if you install MySQL, create some tables, and then reconfigure MySQL to use a different character set and reinstall it.

  With the configure option `--with-extra-charsets=`LIST``, you can define which additional character sets should be compiled into the server. `LIST` is one of the following:

  - A list of character set names separated by spaces

  - `complex` to include all character sets that can't be dynamically loaded

  - `all` to include all character sets into the binaries

  Clients that want to convert characters between the server and the client should use the `SET NAMES` statement. See Section 13.5.3, “`SET` Syntax”, and Section 10.4, “Connection Character Sets and Collations”.

- To configure MySQL with debugging code, use the `--with-debug` option:

      shell> ./configure --with-debug

  This causes a safe memory allocator to be included that can find some errors and that provides output about what is happening. See Section H.1, “Debugging a MySQL Server”.

  As of MySQL 5.0.25, using `--with-debug` to configure MySQL with debugging support enables you to use the `--debug="d,parser_debug"` option when you start the server. This causes the Bison parser that is used to process SQL statements to dump a parser trace to the server's standard error output. Typically, this output is written to the error log.

- If your client programs are using threads, you must compile a thread-safe version of the MySQL client library with the `--enable-thread-safe-client` configure option. This creates a `libmysqlclient_r` library with which you should link your threaded applications. See Section 22.2.15, “How to Make a Threaded Client”.

- It is possible to build MySQL 5.0 with large table support using the `--with-big-tables` option, beginning with MySQL 5.0.4.

  This option causes the variables that store table row counts to be declared as `unsigned long long` rather than `unsigned long`. This enables tables to hold up to approximately 1.844E+19 ((232)2) rows rather than 232 (~4.295E+09) rows. Previously it was necessary to pass `-DBIG_TABLES` to the compiler manually in order to enable this feature.

- Run configure with the `--disable-grant-options` option to cause the the `--bootstrap`, `--skip-grant-tables`, and `--init-file` options for mysqld to be disabled. For Windows, the configure.js script recognizes the `DISABLE_GRANT_OPTIONS` flag, which has the same effect. The capability is available as of MySQL 5.0.34.

- See Section 2.4.18, “Operating System-Specific Notes”, for options that pertain to particular operating systems.

- See Section 5.9.7.2, “Using SSL Connections”, for options that pertain to configuring MySQL to support secure (encrypted) connections.

#### 2.4.14.3. Installing from the Development Source Tree

This section does not apply to MySQL Enterprise Server users.

Caution: You should read this section only if you are interested in helping us test our new code. If you just want to get MySQL up and running on your system, you should use a standard release distribution (either a binary or source distribution).

To obtain our most recent development source tree, first download and install the BitKeeper free client if you do not have it. The client can be obtained from http://www.bitmover.com/bk-client2.0.shar. Note that you will need `gcc` and `make` to build the BitKeeper free client, and patch and tar to use the BitKeeper free client. Note that old 1.1 versions of the BitKeeper free client will not work!

To install the BitKeeper client on Unix, use these commands:

            shell> /bin/sh bk-client2.0.shar
            shell> cd bk-client2.0
            shell> make

If you get a `cc: command not found` error, invoke this command before running `make`:

            shell> make CC=gcc

The step above will create the utility bkf, which is the free BitKeeper client.

To install the BitKeeper client on Windows, use these instructions:

1. Download and install Cygwin from http://cygwin.com.

2. Make sure patch, tar, gcc and make have been installed under Cygwin. You can test this by issuing which `gcc` for each command. If a required tool is not installed, run Cygwin's package manager, select the required tools and install them.

3. For the installation of the BitKeeper free client, use the same installations as given for Unix-like systems above.

For more information on bkf, use:

    shell> bkf --help

After you have installed the BitKeeper client, you can access the MySQL development source tree:

1. Change location to the directory you want to work from, and then use the following command to make a local copy of the MySQL 5.0 branch:

                   shell> bkf clone bk://mysql.bkbits.net/mysql-5.0 mysql-5.0

   In the preceding example, the source tree is set up in the `mysql-5.0/` subdirectory of your current directory.

   The initial download of the source tree may take a while, depending on the speed of your connection. Please be patient.

2. You need GNU make, autoconf 2.58 (or newer), automake 1.8, libtool 1.5, and m4 to run the next set of commands. Even though many operating systems come with their own implementation of make, chances are high that the compilation fails with strange error messages. Therefore, it is highly recommended that you use GNU make (sometimes named gmake) instead.

   Fortunately, a large number of operating systems ship with the GNU toolchain preinstalled or supply installable packages of these. In any case, they can also be downloaded from the following locations:

   - http://www.gnu.org/software/autoconf/

   - http://www.gnu.org/software/automake/

   - http://www.gnu.org/software/libtool/

   - http://www.gnu.org/software/m4/

   - http://www.gnu.org/software/make/

   To configure MySQL 5.0, you also need GNU bison. You should use the latest version of bison where possible. Version 1.75 and version 2.1 are known to work. There have been reported problems with bison 1.875. If you experience problems, upgrade to a later, rather than earlier, version. Versions of bison older than 1.75 may report this error:

       sql_yacc.yy:#####: fatal error: maximum table size (32767) exceeded

   Note: The maximum table size is not actually exceeded; the error is caused by bugs in older versions of bison.

   The following example shows the typical commands required to configure a source tree. The first `cd` command changes location into the top-level directory of the tree; replace `mysql-5.0` with the appropriate directory name.

       shell> cd mysql-5.0
       shell> (cd bdb/dist; sh s_all)
       shell> (cd innobase; autoreconf --force --install)
       shell> autoreconf --force --install
       shell> ./configure  # Add your favorite options here
       shell> make

   Or you can use BUILD/autorun.sh as a shortcut for the following sequence of commands:

       shell> aclocal; autoheader
       shell> libtoolize --automake --force
       shell> automake --force --add-missing; autoconf
       shell> (cd innobase; aclocal; autoheader; autoconf; automake)
       shell> (cd bdb/dist; sh s_all)

   The command lines that change directory into the `innobase` and `bdb/dist` directories are used to configure the `InnoDB` and Berkeley DB (`BDB`) storage engines. You can omit these command lines if you to not require `InnoDB` or `BDB` support.

   If you get some strange errors during this stage, verify that you really have libtool installed.

   A collection of our standard configuration scripts is located in the `BUILD/` subdirectory. You may find it more convenient to use the `BUILD/compile-pentium-debug` script than the preceding set of shell commands. To compile on a different architecture, modify the script by removing flags that are Pentium-specific.

3. When the build is done, run make install. Be careful with this on a production machine; the command may overwrite your live release installation. If you have another installation of MySQL, we recommend that you run ./configure with different values for the `--prefix`, `--with-tcp-port`, and `--unix-socket-path` options than those used for your production server.

4. Play hard with your new installation and try to make the new features crash. Start by running make test. See Section 24.1.2, “MySQL Test Suite”.

5. If you have gotten to the make stage, but the distribution does not compile, please enter the problem into our bugs database using the instructions given in Section 1.8, “How to Report Bugs or Problems”. If you have installed the latest versions of the required GNU tools, and they crash trying to process our configuration files, please report that also. However, if you execute `aclocal` and get a `command not found` error or a similar problem, do not report it. Instead, make sure that all the necessary tools are installed and that your `PATH` variable is set correctly so that your shell can find them.

6. After initially copying the repository with bkf to obtain the source tree, you should use pull option to periodically update your local copy. To do this any time after you have set up the repository, use this command:

       shell> bkf pull

7. You can examine the changeset comments for the tree by using the `changes` option to bkf:

       shell> bkf changes

   To get a list of the changes that would be applied with the next `bkf pull`:

       shell> bkf changes -R

   To obtain a patch file for a specific changeset (`CSETID`), use:

       shell> bkf changes -vvrCSETID

   If you see diffs or code that you have a question about, do not hesitate to send email to the MySQL Internals mailing list. (See Section 1.7.1, “MySQL Mailing Lists”.) Also, if you think you have a better idea on how to do something, send an email message to the list with your proposed patch.

You can also browse changesets, comments, and source code online. To browse this information for MySQL 5.0, go to http://mysql.bkbits.net:8080/mysql-5.0.

#### 2.4.14.4. Dealing with Problems Compiling MySQL

This section does not apply to MySQL Enterprise Server users.

All MySQL programs compile cleanly for us with no warnings on Solaris or Linux using gcc. On other systems, warnings may occur due to differences in system include files. See Section 2.4.14.5, “MIT-pthreads Notes”, for warnings that may occur when using MIT-pthreads. For other problems, check the following list.

The solution to many problems involves reconfiguring. If you do need to reconfigure, take note of the following:

- If configure is run after it has previously been run, it may use information that was gathered during its previous invocation. This information is stored in `config.cache`. When configure starts up, it looks for that file and reads its contents if it exists, on the assumption that the information is still correct. That assumption is invalid when you reconfigure.

- Each time you run configure, you must run make again to recompile. However, you may want to remove old object files from previous builds first because they were compiled using different configuration options.

To prevent old configuration information or object files from being used, run these commands before re-running configure:

    shell> rm config.cache
    shell> make clean

Alternatively, you can run make distclean.

The following list describes some of the problems when compiling MySQL that have been found to occur most often:

- If you get errors such as the ones shown here when compiling `sql_yacc.cc`, you probably have run out of memory or swap space:

      Internal compiler error: program cc1plus got fatal signal 11
      Out of virtual memory
      Virtual memory exhausted

  The problem is that gcc requires a huge amount of memory to compile `sql_yacc.cc` with inline functions. Try running configure with the `--with-low-memory` option:

      shell> ./configure --with-low-memory

  This option causes `-fno-inline` to be added to the compile line if you are using gcc and `-O0` if you are using something else. You should try the `--with-low-memory` option even if you have so much memory and swap space that you think you can't possibly have run out. This problem has been observed to occur even on systems with generous hardware configurations, and the `--with-low-memory` option usually fixes it.

- By default, configure picks c++ as the compiler name and GNU c++ links with `-lg++`. If you are using gcc, that behavior can cause problems during configuration such as this:

      configure: error: installation or configuration problem:
      C++ compiler cannot create executables.

  You might also observe problems during compilation related to g++, `libg++`, or `libstdc++`.

  One cause of these problems is that you may not have g++, or you may have g++ but not `libg++`, or `libstdc++`. Take a look at the `config.log` file. It should contain the exact reason why your C++ compiler didn't work. To work around these problems, you can use gcc as your C++ compiler. Try setting the environment variable `CXX` to `"gcc -O3"`. For example:

      shell> CXX="gcc -O3" ./configure

  This works because gcc compiles C++ source files as well as g++ does, but does not link in `libg++` or `libstdc++` by default.

  Another way to fix these problems is to install g++, `libg++`, and `libstdc++`. However, we recommend that you not use `libg++` or `libstdc++` with MySQL because this only increases the binary size of mysqld without providing any benefits. Some versions of these libraries have also caused strange problems for MySQL users in the past.

- If your compile fails with errors such as any of the following, you must upgrade your version of make to GNU make:

      making all in mit-pthreads
      make: Fatal error in reader: Makefile, line 18:
      Badly formed macro assignment

  Or:

      make: file `Makefile' line 18: Must be a separator (:

  Or:

      pthread.h: No such file or directory

  Solaris and FreeBSD are known to have troublesome make programs.

  GNU make 3.75 is known to work.

- If you want to define flags to be used by your C or C++ compilers, do so by adding the flags to the `CFLAGS` and `CXXFLAGS` environment variables. You can also specify the compiler names this way using `CC` and `CXX`. For example:

      shell> CC=gcc
      shell> CFLAGS=-O3
      shell> CXX=gcc
      shell> CXXFLAGS=-O3
      shell> export CC CFLAGS CXX CXXFLAGS

  See Section 2.4.3.5, “MySQL Binaries Compiled by MySQL AB”, for a list of flag definitions that have been found to be useful on various systems.

- If you get errors such as those shown here when compiling mysqld, configure did not correctly detect the type of the last argument to `accept()`, `getsockname()`, or `getpeername()`:

      cxx: Error: mysqld.cc, line 645: In this statement, the referenced
           type of the pointer value ''length'' is ''unsigned long'',
           which is not compatible with ''int''.
      new_sock = accept(sock, (struct sockaddr *)&cAddr, &length);

  To fix this, edit the `config.h` file (which is generated by configure). Look for these lines:

      /* Define as the base type of the last arg to accept */
      #define SOCKET_SIZE_TYPE XXX

  Change `XXX` to `size_t` or `int`, depending on your operating system. (You must do this each time you run configure because configure regenerates `config.h`.)

- The `sql_yacc.cc` file is generated from `sql_yacc.yy`. Normally, the build process does not need to create `sql_yacc.cc` because MySQL comes with a pre-generated copy. However, if you do need to re-create it, you might encounter this error:

      "sql_yacc.yy", line xxx fatal: default action causes potential...

  This is a sign that your version of yacc is deficient. You probably need to install bison (the GNU version of yacc) and use that instead.

- On Debian Linux 3.0, you need to install `gawk` instead of the default `mawk` if you want to compile MySQL with Berkeley DB support.

- If you need to debug mysqld or a MySQL client, run configure with the `--with-debug` option, and then recompile and link your clients with the new client library. See Section H.2, “Debugging a MySQL Client”.

- If you get a compilation error on Linux (for example, SuSE Linux 8.1 or Red Hat Linux 7.3) similar to the following one, you probably do not have g++ installed:

      libmysql.c:1329: warning: passing arg 5 of `gethostbyname_r' from
      incompatible pointer type
      libmysql.c:1329: too few arguments to function `gethostbyname_r'
      libmysql.c:1329: warning: assignment makes pointer from integer
      without a cast
      make[2]: *** [libmysql.lo] Error 1

  By default, the configure script attempts to determine the correct number of arguments by using g++ (the GNU C++ compiler). This test yields incorrect results if g++ is not installed. There are two ways to work around this problem:

  - Make sure that the GNU C++ g++ is installed. On some Linux distributions, the required package is called `gpp`; on others, it is named gcc-c++.

  - Use gcc as your C++ compiler by setting the `CXX` environment variable to gcc:

        export CXX="gcc"

  You must run configure again after making either of those changes.

#### 2.4.14.5. MIT-pthreads Notes

This section does not apply to MySQL Enterprise Server users.

This section describes some of the issues involved in using MIT-pthreads.

On Linux, you should not use MIT-pthreads. Use the installed LinuxThreads implementation instead. See Section 2.4.18.1, “Linux Notes”.

If your system does not provide native thread support, you should build MySQL using the MIT-pthreads package. This includes older FreeBSD systems, SunOS 4.x, Solaris 2.4 and earlier, and some others. See Section 2.4.2, “Operating Systems Supported by MySQL Community Server”.

MIT-pthreads is not part of the MySQL 5.0 source distribution. If you require this package, you need to download it separately from http://dev.mysql.com/Downloads/Contrib/pthreads-1_60_beta6-mysql.tar.gz

After downloading, extract this source archive into the top level of the MySQL source directory. It creates a new subdirectory named `mit-pthreads`.

- On most systems, you can force MIT-pthreads to be used by running configure with the `--with-mit-threads` option:

      shell> ./configure --with-mit-threads

  Building in a non-source directory is not supported when using MIT-pthreads because we want to minimize our changes to this code.

- The checks that determine whether to use MIT-pthreads occur only during the part of the configuration process that deals with the server code. If you have configured the distribution using `--without-server` to build only the client code, clients do not know whether MIT-pthreads is being used and use Unix socket file connections by default. Because Unix socket files do not work under MIT-pthreads on some platforms, this means you need to use `-h` or `--host` with a value other than `localhost` when you run client programs.

- When MySQL is compiled using MIT-pthreads, system locking is disabled by default for performance reasons. You can tell the server to use system locking with the `--external-locking` option. This is needed only if you want to be able to run two MySQL servers against the same data files, but that is not recommended, anyway.

- Sometimes the pthread `bind()` command fails to bind to a socket without any error message (at least on Solaris). The result is that all connections to the server fail. For example:

      shell> mysqladmin version
      mysqladmin: connect to server at '' failed;
      error: 'Can't connect to mysql server on localhost (146)'

  The solution to this problem is to kill the mysqld server and restart it. This has happened to us only when we have forcibly stopped the server and restarted it immediately.

- With MIT-pthreads, the `sleep()` system call isn't interruptible with `SIGINT` (break). This is noticeable only when you run mysqladmin --sleep. You must wait for the `sleep()` call to terminate before the interrupt is served and the process stops.

- When linking, you might receive warning messages like these (at least on Solaris); they can be ignored:

      ld: warning: symbol `_iob' has differing sizes:
          (file /my/local/pthreads/lib/libpthread.a(findfp.o) value=0x4;
      file /usr/lib/libc.so value=0x140);
          /my/local/pthreads/lib/libpthread.a(findfp.o) definition taken
      ld: warning: symbol `__iob' has differing sizes:
          (file /my/local/pthreads/lib/libpthread.a(findfp.o) value=0x4;
      file /usr/lib/libc.so value=0x140);
          /my/local/pthreads/lib/libpthread.a(findfp.o) definition taken

- Some other warnings also can be ignored:

      implicit declaration of function `int strtoll(...)'
      implicit declaration of function `int strtoul(...)'

- We have not been able to make `readline` work with MIT-pthreads. (This is not necessary, but may be of interest to some.)

#### 2.4.14.6. Installing MySQL from Source on Windows

This section does not apply to MySQL Enterprise Server users.

These instructions describe how to build binaries from source for MySQL 5.0 on Windows. Instructions are provided for building binaries from a standard source distribution or from the BitKeeper tree that contains the latest development source.

Note: The instructions here are strictly for users who want to test MySQL on Microsoft Windows from the latest source distribution or from the BitKeeper tree. For production use, MySQL AB does not advise using a MySQL server built by yourself from source. Normally, it is best to use precompiled binary distributions of MySQL that are built specifically for optimal performance on Windows by MySQL AB. Instructions for installing binary distributions are available in Section 2.4.8, “Installing MySQL on Windows”.

To build MySQL on Windows from source, you must satisfy the following system, compiler, and resource requirements:

- Windows XP, Windows 2000, or newer version

- Visual Studio .Net 2003 (7.1) compiler system

- 3GB to 5GB of disk space

The exact system requirements can be found here: http://msdn.microsoft.com/vstudio/Previous/2003/sysreqs/default.aspx

You also need a MySQL source distribution for Windows, which can be obtained two ways:

- Obtain a Windows source distribution packaged by MySQL AB for the particular version of MySQL in which you are interested. These are available from http://dev.mysql.com/downloads/.

- Package a source distribution yourself from the latest BitKeeper developer source tree. If you plan to do this, you must create the package on a Unix system and then transfer it to your Windows system. (Some of the configuration and build steps require tools that work only on Unix.) The BitKeeper approach thus requires:

  - A system running Unix, or a Unix-like system such as Linux.

  - BitKeeper installed on that system. See Section 2.4.14.3, “Installing from the Development Source Tree”, for instructions how to download and install BitKeeper.

If you are using a Windows source distribution, you can go directly to Section 2.4.14.6.1, “Building MySQL from Source Using VC++”. To build from the BitKeeper tree, proceed to Section 2.4.14.6.2, “Creating a Windows Source Package from the Latest Development Source”.

If you find something not working as expected, or you have suggestions about ways to improve the current build process on Windows, please send a message to the `win32` mailing list. See Section 1.7.1, “MySQL Mailing Lists”.

##### 2.4.14.6.1. Building MySQL from Source Using VC++

This section does not apply to MySQL Enterprise Server users.

Note: VC++ workspace files for MySQL 4.1 and above are compatible with Microsoft Visual Studio 7.1 and tested by MySQL AB staff before each release.

Follow this procedure to build MySQL:

1. Create a work directory (for example, `C:\workdir`).

2. Unpack the source distribution in the aforementioned directory using WinZip or another Windows tool that can read `.zip` files.

3. Start Visual Studio .Net 2003 (7.1).

4. From the File menu, select Open Solution....

5. Open the `mysql.sln` solution you find in the work directory.

6. From the Build menu, select Configuration Manager....

7. In the Active Solution Configuration pop-up menu, select the configuration to use. You likely want to use one of nt (normal server, not for Windows 98/ME), Max nt (more engines and features, not for 98/ME) or Debug configuration.

8. From the Build menu, select Build Solution.

9. Debug versions of the programs and libraries are placed in the `client_debug` and `lib_debug` directories. Release versions of the programs and libraries are placed in the `client_release` and `lib_release` directories.

10. Test the server. The server built using the preceding instructions expects that the MySQL base directory and data directory are `C:\mysql` and `C:\mysql\data` by default. If you want to test your server using the source tree root directory and its data directory as the base directory and data directory, you need to tell the server their pathnames. You can either do this on the command line with the `--basedir` and `--datadir` options, or by placing appropriate options in an option file. (See Section 4.3.2, “Using Option Files”.) If you have an existing data directory elsewhere that you want to use, you can specify its pathname instead.

11. Start your server from the `client_release` or `client_debug` directory, depending on which server you built or want to use. The general server startup instructions are in Section 2.4.8, “Installing MySQL on Windows”. You must adapt the instructions appropriately if you want to use a different base directory or data directory.

12. When the server is running in standalone fashion or as a service based on your configuration, try to connect to it from the mysql interactive command-line utility that exists in your `client_release` or `client_debug` directory.

When you are satisfied that the programs you have built are working correctly, stop the server. Then install MySQL as follows:

1. Create the directories where you want to install MySQL. For example, to install into `C:\mysql`, use these commands:

       C:\> mkdir C:\mysql
       C:\> mkdir C:\mysql\bin
       C:\> mkdir C:\mysql\data
       C:\> mkdir C:\mysql\share
       C:\> mkdir C:\mysql\scripts

   If you want to compile other clients and link them to MySQL, you should also create several additional directories:

       C:\> mkdir C:\mysql\include
       C:\> mkdir C:\mysql\lib
       C:\> mkdir C:\mysql\lib\debug
       C:\> mkdir C:\mysql\lib\opt

   If you want to benchmark MySQL, create this directory:

       C:\> mkdir C:\mysql\sql-bench

   Benchmarking requires Perl support. See Section 2.4.19, “Perl Installation Notes”.

2. From the `workdir` directory, copy into the `C:\mysql` directory the following directories:

       C:\> cd \workdir
       C:\workdir> copy client_release\*.exe C:\mysql\bin
       C:\workdir> copy client_debug\mysqld.exe C:\mysql\bin\mysqld-debug.exe
       C:\workdir> xcopy scripts\*.* C:\mysql\scripts /E
       C:\workdir> xcopy share\*.* C:\mysql\share /E

   If you want to compile other clients and link them to MySQL, you should also copy several libraries and header files:

       C:\workdir> copy lib_debug\mysqlclient.lib C:\mysql\lib\debug
       C:\workdir> copy lib_debug\libmysql.* C:\mysql\lib\debug
       C:\workdir> copy lib_debug\zlib.* C:\mysql\lib\debug
       C:\workdir> copy lib_release\mysqlclient.lib C:\mysql\lib\opt
       C:\workdir> copy lib_release\libmysql.* C:\mysql\lib\opt
       C:\workdir> copy lib_release\zlib.* C:\mysql\lib\opt
       C:\workdir> copy include\*.h C:\mysql\include
       C:\workdir> copy libmysql\libmysql.def C:\mysql\include

   If you want to benchmark MySQL, you should also do this:

       C:\workdir> xcopy sql-bench\*.* C:\mysql\bench /E

Set up and start the server in the same way as for binary Windows distributions. See Section 2.4.8, “Installing MySQL on Windows”.

##### 2.4.14.6.2. Creating a Windows Source Package from the Latest Development Source

This section does not apply to MySQL Enterprise Server users.

To create a Windows source package from the current BitKeeper source tree, use the instructions here. This procedure must be performed on a system running a Unix or Unix-like operating system because some of the configuration and build steps require tools that work only on Unix. For example, the following procedure is known to work well on Linux.

1. Copy the BitKeeper source tree for MySQL 5.0. For instructions on how to do this, see Section 2.4.14.3, “Installing from the Development Source Tree”.

2. Configure and build the distribution so that you have a server binary to work with. One way to do this is to run the following command in the top-level directory of your source tree:

       shell> ./BUILD/compile-pentium-max

3. After making sure that the build process completed successfully, run the following utility script from top-level directory of your source tree:

       shell> ./scripts/make_win_src_distribution

   This script creates a Windows source package to be used on your Windows system. You can supply different options to the script based on your needs. It accepts the following options:

   - `--help`

     Display a help message.

   - `--debug`

     Print information about script operations, do not create package.

   - `--tmp`

     Specify the temporary location.

   - `--suffix`

     The suffix name for the package.

   - `--dirname`

     Directory name to copy files (intermediate).

   - `--silent`

     Do not print verbose list of files processed.

   - `--tar`

     Create `tar.gz` package instead of `.zip` package.

   By default, make_win_src_distribution creates a Zip-format archive with the name `mysql-`VERSION`-win-src.zip`, where `VERSION` represents the version of your MySQL source tree.

4. Copy or upload the Windows source package that you have just created to your Windows machine. To compile it, use the instructions in Section 2.4.14.6.1, “Building MySQL from Source Using VC++”.

#### 2.4.14.7. Compiling MySQL Clients on Windows

This section does not apply to MySQL Enterprise Server users.

In your source files, you should include `my_global.h` before `mysql.h`:

    #include <my_global.h>
    #include <mysql.h>

`my_global.h` includes any other files needed for Windows compatibility (such as `windows.h`) if you compile your program on Windows.

You can either link your code with the dynamic `libmysql.lib` library, which is just a wrapper to load in `libmysql.dll` on demand, or link with the static `mysqlclient.lib` library.

The MySQL client libraries are compiled as threaded libraries, so you should also compile your code to be multi-threaded.

### 2.4.15. Post-Installation Setup and Testing

After installing MySQL, there are some issues that you should address. For example, on Unix, you should initialize the data directory and create the MySQL grant tables. On all platforms, an important security concern is that the initial accounts in the grant tables have no passwords. You should assign passwords to prevent unauthorized access to the MySQL server. Optionally, you can create time zone tables to enable recognition of named time zones.

The following sections include post-installation procedures that are specific to Windows systems and to Unix systems. Another section, Section 2.4.15.2.3, “Starting and Troubleshooting the MySQL Server”, applies to all platforms; it describes what to do if you have trouble getting the server to start. Section 2.4.15.3, “Securing the Initial MySQL Accounts”, also applies to all platforms. You should follow its instructions to make sure that you have properly protected your MySQL accounts by assigning passwords to them.

When you are ready to create additional user accounts, you can find information on the MySQL access control system and account management in Section 5.8, “The MySQL Access Privilege System”, and Section 5.9, “MySQL User Account Management”.

#### 2.4.15.1. Windows Post-Installation Procedures

On Windows, the data directory and the grant tables do not have to be created. MySQL Windows distributions include the grant tables with a set of preinitialized accounts in the `mysql` database under the data directory. It is unnecessary to run the mysql_install_db script that is used on Unix. Regarding passwords, if you installed MySQL using the Windows Installation Wizard, you may have already assigned passwords to the accounts. (See Section 2.4.8.3, “Using the MySQL Installation Wizard”.) Otherwise, use the password-assignment procedure given in Section 2.4.15.3, “Securing the Initial MySQL Accounts”.

Before setting up passwords, you might want to try running some client programs to make sure that you can connect to the server and that it is operating properly. Make sure that the server is running (see Section 2.4.8.9, “Starting the Server for the First Time”), and then issue the following commands to verify that you can retrieve information from the server. The output should be similar to what is shown here:

    C:\> C:\mysql\bin\mysqlshow
    +-----------+
    | Databases |
    +-----------+
    | mysql     |
    | test      |
    +-----------+

    C:\> C:\mysql\bin\mysqlshow mysql
    Database: mysql
    +---------------------------+
    |          Tables           |
    +---------------------------+
    | columns_priv              |
    | db                        |
    | func                      |
    | help_category             |
    | help_keyword              |
    | help_relation             |
    | help_topic                |
    | host                      |
    | proc                      |
    | procs_priv                |
    | tables_priv               |
    | time_zone                 |
    | time_zone_leap_second     |
    | time_zone_name            |
    | time_zone_transition      |
    | time_zone_transition_type |
    | user                      |
    +---------------------------+

    C:\> C:\mysql\bin\mysql -e "SELECT Host,Db,User FROM db" mysql
    +------+-------+------+
    | host | db    | user |
    +------+-------+------+
    | %    | test% |      |
    +------+-------+------+

If you are running a version of Windows that supports services and you want the MySQL server to run automatically when Windows starts, see Section 2.4.8.11, “Starting MySQL as a Windows Service”.

#### 2.4.15.2. Unix Post-Installation Procedures

After installing MySQL on Unix, you need to initialize the grant tables, start the server, and make sure that the server works satisfactorily. You may also wish to arrange for the server to be started and stopped automatically when your system starts and stops. You should also assign passwords to the accounts in the grant tables.

On Unix, the grant tables are set up by the mysql_install_db program. For some installation methods, this program is run for you automatically:

- If you install MySQL on Linux using RPM distributions, the server RPM runs mysql_install_db.

- If you install MySQL on Mac OS X using a PKG distribution, the installer runs mysql_install_db.

Otherwise, you will need to run mysql_install_db yourself.

The following procedure describes how to initialize the grant tables (if that has not previously been done) and then start the server. It also suggests some commands that you can use to test whether the server is accessible and working properly. For information about starting and stopping the server automatically, see Section 2.4.15.2.2, “Starting and Stopping MySQL Automatically”.

After you complete the procedure and have the server running, you should assign passwords to the accounts created by mysql_install_db. Instructions for doing so are given in Section 2.4.15.3, “Securing the Initial MySQL Accounts”.

In the examples shown here, the server runs under the user ID of the `mysql` login account. This assumes that such an account exists. Either create the account if it does not exist, or substitute the name of a different existing login account that you plan to use for running the server.

1. Change location into the top-level directory of your MySQL installation, represented here by `BASEDIR`:

       shell> cd BASEDIR

   `BASEDIR` is likely to be something like `/usr/local/mysql` or `/usr/local`. The following steps assume that you are located in this directory.

2. If necessary, run the mysql_install_db program to set up the initial MySQL grant tables containing the privileges that determine how users are allowed to connect to the server. You'll need to do this if you used a distribution type for which the installation procedure doesn't run the program for you.

   Typically, mysql_install_db needs to be run only the first time you install MySQL, so you can skip this step if you are upgrading an existing installation, However, mysql_install_db does not overwrite any existing privilege tables, so it should be safe to run in any circumstances.

   To initialize the grant tables, use one of the following commands, depending on whether mysql_install_db is located in the `bin` or `scripts` directory:

       shell> bin/mysql_install_db --user=mysql
       shell> scripts/mysql_install_db --user=mysql

   The mysql_install_db script creates the server's data directory. Under the data directory, it creates directories for the `mysql` database that holds all database privileges and the `test` database that you can use to test MySQL. The script also creates privilege table entries for `root` and anonymous-user accounts. The accounts have no passwords initially. A description of their initial privileges is given in Section 2.4.15.3, “Securing the Initial MySQL Accounts”. Briefly, these privileges allow the MySQL `root` user to do anything, and allow anybody to create or use databases with a name of `test` or starting with `test_`.

   It is important to make sure that the database directories and files are owned by the `mysql` login account so that the server has read and write access to them when you run it later. To ensure this, the `--user` option should be used as shown if you run mysql_install_db as `root`. Otherwise, you should execute the script while logged in as `mysql`, in which case you can omit the `--user` option from the command.

   mysql_install_db creates several tables in the `mysql` database, including `user`, `db`, `host`, `tables_priv`, `columns_priv`, `func`, and others. See Section 5.8, “The MySQL Access Privilege System”, for a complete listing and description of these tables.

   If you don't want to have the `test` database, you can remove it with mysqladmin -u root drop test after starting the server.

   If you have trouble with mysql_install_db at this point, see Section 2.4.15.2.1, “Problems Running mysql_install_db”.

3. Start the MySQL server:

       shell> bin/mysqld_safe --user=mysql &

   It is important that the MySQL server be run using an unprivileged (non-`root`) login account. To ensure this, the `--user` option should be used as shown if you run `mysql_safe` as system `root`. Otherwise, you should execute the script while logged in to the system as `mysql`, in which case you can omit the `--user` option from the command.

   Further instructions for running MySQL as an unprivileged user are given in Section 5.7.5, “How to Run MySQL as a Normal User”.

   If you neglected to create the grant tables before proceeding to this step, the following message appears in the error log file when you start the server:

       mysqld: Can't find file: 'host.frm'

   If you have other problems starting the server, see Section 2.4.15.2.3, “Starting and Troubleshooting the MySQL Server”.

4. Use mysqladmin to verify that the server is running. The following commands provide simple tests to check whether the server is up and responding to connections:

       shell> bin/mysqladmin version
       shell> bin/mysqladmin variables

   The output from mysqladmin version varies slightly depending on your platform and version of MySQL, but should be similar to that shown here:

       shell> bin/mysqladmin version
       mysqladmin  Ver 14.12 Distrib 5.0.34, for pc-linux-gnu on i686
       Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
       This software comes with ABSOLUTELY NO WARRANTY. This is free software,
       and you are welcome to modify and redistribute it under the GPL license

       Server version          5.0.34-Max
       Protocol version        10
       Connection              Localhost via UNIX socket
       UNIX socket             /var/lib/mysql/mysql.sock
       Uptime:                 14 days 5 hours 5 min 21 sec

       Threads: 1  Questions: 366  Slow queries: 0
       Opens: 0  Flush tables: 1  Open tables: 19
       Queries per second avg: 0.000

   To see what else you can do with mysqladmin, invoke it with the `--help` option.

5. Verify that you can shut down the server:

       shell> bin/mysqladmin -u root shutdown

6. Verify that you can start the server again. Do this by using mysqld_safe or by invoking mysqld directly. For example:

       shell> bin/mysqld_safe --user=mysql --log &

   If mysqld_safe fails, see Section 2.4.15.2.3, “Starting and Troubleshooting the MySQL Server”.

7. Run some simple tests to verify that you can retrieve information from the server. The output should be similar to what is shown here:

       shell> bin/mysqlshow
       +-----------+
       | Databases |
       +-----------+
       | mysql     |
       | test      |
       +-----------+

       shell> bin/mysqlshow mysql
       Database: mysql
       +---------------------------+
       |          Tables           |
       +---------------------------+
       | columns_priv              |
       | db                        |
       | func                      |
       | help_category             |
       | help_keyword              |
       | help_relation             |
       | help_topic                |
       | host                      |
       | proc                      |
       | procs_priv                |
       | tables_priv               |
       | time_zone                 |
       | time_zone_leap_second     |
       | time_zone_name            |
       | time_zone_transition      |
       | time_zone_transition_type |
       | user                      |
       +---------------------------+

       shell> bin/mysql -e "SELECT Host,Db,User FROM db" mysql
       +------+--------+------+
       | host | db     | user |
       +------+--------+------+
       | %    | test   |      |
       | %    | test_% |      |
       +------+--------+------+

8. There is a benchmark suite in the `sql-bench` directory (under the MySQL installation directory) that you can use to compare how MySQL performs on different platforms. The benchmark suite is written in Perl. It requires the Perl DBI module that provides a database-independent interface to the various databases, and some other additional Perl modules:

       DBI
       DBD::mysql
       Data::Dumper
       Data::ShowTable

   These modules can be obtained from CPAN (http://www.cpan.org/). See also Section 2.4.19.1, “Installing Perl on Unix”.

   The `sql-bench/Results` directory contains the results from many runs against different databases and platforms. To run all tests, execute these commands:

       shell> cd sql-bench
       shell> perl run-all-tests

   If you don't have the `sql-bench` directory, you probably installed MySQL using RPM files other than the source RPM. (The source RPM includes the `sql-bench` benchmark directory.) In this case, you must first install the benchmark suite before you can use it. There are separate benchmark RPM files named `mysql-bench-`VERSION`-i386.rpm` that contain benchmark code and data.

   If you have a source distribution, there are also tests in its `tests` subdirectory that you can run. For example, to run `auto_increment.tst`, execute this command from the top-level directory of your source distribution:

       shell> mysql -vvf test < ./tests/auto_increment.tst

   The expected result of the test can be found in the `./tests/auto_increment.res` file.

9. At this point, you should have the server running. However, none of the initial MySQL accounts have a password, so you should assign passwords using the instructions found in Section 2.4.15.3, “Securing the Initial MySQL Accounts”.

The MySQL 5.0 installation procedure creates time zone tables in the `mysql` database. However, you must populate the tables manually using the instructions in Section 5.11.8, “MySQL Server Time Zone Support”.

##### 2.4.15.2.1. Problems Running mysql_install_db

This section does not apply to MySQL Enterprise Server users.

The purpose of the mysql_install_db script is to generate new MySQL privilege tables. It does not overwrite existing MySQL privilege tables, and it does not affect any other data.

If you want to re-create your privilege tables, first stop the mysqld server if it's running. Then rename the `mysql` directory under the data directory to save it, and then run mysql_install_db. Suppose that your current directory is the MySQL installation directory and that mysql_install_db is located in the `bin` directory and the data directory is named `data`. To rename the `mysql` database and re-run mysql_install_db, use these commands.

    shell> mv data/mysql data/mysql.old
    shell> bin/mysql_install_db --user=mysql

When you run mysql_install_db, you might encounter the following problems:

- mysql_install_db fails to install the grant tables

  You may find that mysql_install_db fails to install the grant tables and terminates after displaying the following messages:

      Starting mysqld daemon with databases from XXXXXX
      mysqld ended

  In this case, you should examine the error log file very carefully. The log should be located in the directory `XXXXXX` named by the error message and should indicate why mysqld didn't start. If you do not understand what happened, include the log when you post a bug report. See Section 1.8, “How to Report Bugs or Problems”.

- There is a mysqld process running

  This indicates that the server is running, in which case the grant tables have probably been created already. If so, there is no need to run mysql_install_db at all because it needs to be run only once (when you install MySQL the first time).

- Installing a second mysqld server does not work when one server is running

  This can happen when you have an existing MySQL installation, but want to put a new installation in a different location. For example, you might have a production installation, but you want to create a second installation for testing purposes. Generally the problem that occurs when you try to run a second server is that it tries to use a network interface that is in use by the first server. In this case, you should see one of the following error messages:

      Can't start server: Bind on TCP/IP port:
      Address already in use
      Can't start server: Bind on unix socket...

  For instructions on setting up multiple servers, see Section 5.13, “Running Multiple MySQL Servers on the Same Machine”.

- You do not have write access to the `/tmp` directory

  If you do not have write access to create temporary files or a Unix socket file in the default location (the `/tmp` directory), an error occurs when you run mysql_install_db or the mysqld server.

  You can specify different locations for the temporary directory and Unix socket file by executing these commands prior to starting mysql_install_db or mysqld, where `some_tmp_dir` is the full pathname to some directory for which you have write permission:

      shell> TMPDIR=/some_tmp_dir/
      shell> MYSQL_UNIX_PORT=/some_tmp_dir/mysql.sock
      shell> export TMPDIR MYSQL_UNIX_PORT

  Then you should be able to run mysql_install_db and start the server with these commands:

      shell> bin/mysql_install_db --user=mysql
      shell> bin/mysqld_safe --user=mysql &

  If mysql_install_db is located in the `scripts` directory, modify the first command to `scripts/mysql_install_db`.

  See Section B.4.5, “How to Protect or Change the MySQL Unix Socket File”, and Appendix I, Environment Variables.

There are some alternatives to running the mysql_install_db script provided in the MySQL distribution:

- If you want the initial privileges to be different from the standard defaults, you can modify mysql_install_db before you run it. However, it is preferable to use `GRANT` and `REVOKE` to change the privileges after the grant tables have been set up. In other words, you can run mysql_install_db, and then use `mysql -u root mysql` to connect to the server as the MySQL `root` user so that you can issue the necessary `GRANT` and `REVOKE` statements.

  If you want to install MySQL on several machines with the same privileges, you can put the `GRANT` and `REVOKE` statements in a file and execute the file as a script using `mysql` after running mysql_install_db. For example:

      shell> bin/mysql_install_db --user=mysql
      shell> bin/mysql -u root < your_script_file

  By doing this, you can avoid having to issue the statements manually on each machine.

- It is possible to re-create the grant tables completely after they have previously been created. You might want to do this if you're just learning how to use `GRANT` and `REVOKE` and have made so many modifications after running mysql_install_db that you want to wipe out the tables and start over.

  To re-create the grant tables, remove all the `.frm`, `.MYI`, and `.MYD` files in the `mysql` database directory. Then run the mysql_install_db script again.

- You can start mysqld manually using the `--skip-grant-tables` option and add the privilege information yourself using mysql:

      shell> bin/mysqld_safe --user=mysql --skip-grant-tables &
      shell> bin/mysql mysql

  From mysql, manually execute the SQL commands contained in mysql_install_db. Make sure that you run mysqladmin flush-privileges or mysqladmin reload afterward to tell the server to reload the grant tables.

  Note that by not using mysql_install_db, you not only have to populate the grant tables manually, you also have to create them first.

##### 2.4.15.2.2. Starting and Stopping MySQL Automatically

Generally, you start the mysqld server in one of these ways:

- By invoking mysqld directly. This works on any platform.

- By running the MySQL server as a Windows service. This can be done on versions of Windows that support services (such as NT, 2000, XP, and 2003). The service can be set to start the server automatically when Windows starts, or as a manual service that you start on request. For instructions, see Section 2.4.8.11, “Starting MySQL as a Windows Service”.

- By invoking mysqld_safe, which tries to determine the proper options for mysqld and then runs it with those options. This script is used on Unix and Unix-like systems. See Section 5.4.1, “mysqld_safe — MySQL Server Startup Script”.

- By invoking mysql.server. This script is used primarily at system startup and shutdown on systems that use System V-style run directories, where it usually is installed under the name `mysql`. The mysql.server script starts the server by invoking mysqld_safe. See Section 5.4.2, “mysql.server — MySQL Server Startup Script”.

- On Mac OS X, you can install a separate MySQL Startup Item package to enable the automatic startup of MySQL on system startup. The Startup Item starts the server by invoking mysql.server. See Section 2.4.10, “Installing MySQL on Mac OS X”, for details.

The mysqld_safe and mysql.server scripts and the Mac OS X Startup Item can be used to start the server manually, or automatically at system startup time. mysql.server and the Startup Item also can be used to stop the server.

To start or stop the server manually using the mysql.server script, invoke it with `start` or `stop` arguments:

    shell> mysql.server start
    shell> mysql.server stop

Before mysql.server starts the server, it changes location to the MySQL installation directory, and then invokes mysqld_safe. If you want the server to run as some specific user, add an appropriate `user` option to the `[mysqld]` group of the `/etc/my.cnf` option file, as shown later in this section. (It is possible that you will need to edit mysql.server if you've installed a binary distribution of MySQL in a non-standard location. Modify it to `cd` into the proper directory before it runs mysqld_safe. If you do this, your modified version of mysql.server may be overwritten if you upgrade MySQL in the future, so you should make a copy of your edited version that you can reinstall.)

mysql.server stop stops the server by sending a signal to it. You can also stop the server manually by executing mysqladmin shutdown.

To start and stop MySQL automatically on your server, you need to add start and stop commands to the appropriate places in your `/etc/rc*` files.

If you use the Linux server RPM package (`MySQL-server-`VERSION`.rpm`), the mysql.server script is installed in the `/etc/init.d` directory with the name `mysql`. You need not install it manually. See Section 2.4.9, “Installing MySQL on Linux”, for more information on the Linux RPM packages.

Some vendors provide RPM packages that install a startup script under a different name such as mysqld.

If you install MySQL from a source distribution or using a binary distribution format that does not install mysql.server automatically, you can install it manually. The script can be found in the `support-files` directory under the MySQL installation directory or in a MySQL source tree.

To install mysql.server manually, copy it to the `/etc/init.d` directory with the name mysql, and then make it executable. Do this by changing location into the appropriate directory where mysql.server is located and executing these commands:

    shell> cp mysql.server /etc/init.d/mysql
    shell> chmod +x /etc/init.d/mysql

Older Red Hat systems use the `/etc/rc.d/init.d` directory rather than `/etc/init.d`. Adjust the preceding commands accordingly. Alternatively, first create `/etc/init.d` as a symbolic link that points to `/etc/rc.d/init.d`:

    shell> cd /etc
    shell> ln -s rc.d/init.d .

After installing the script, the commands needed to activate it to run at system startup depend on your operating system. On Linux, you can use `chkconfig`:

    shell> chkconfig --add mysql

On some Linux systems, the following command also seems to be necessary to fully enable the mysql script:

    shell> chkconfig --level 345 mysql on

On FreeBSD, startup scripts generally should go in `/usr/local/etc/rc.d/`. The `rc(8)` manual page states that scripts in this directory are executed only if their basename matches the `*.sh` shell filename pattern. Any other files or directories present within the directory are silently ignored. In other words, on FreeBSD, you should install the `mysql.server` script as `/usr/local/etc/rc.d/mysql.server.sh` to enable automatic startup.

As an alternative to the preceding setup, some operating systems also use `/etc/rc.local` or `/etc/init.d/boot.local` to start additional services on startup. To start up MySQL using this method, you could append a command like the one following to the appropriate startup file:

    /bin/sh -c 'cd /usr/local/mysql; ./bin/mysqld_safe --user=mysql &'

For other systems, consult your operating system documentation to see how to install startup scripts.

You can add options for mysql.server in a global `/etc/my.cnf` file. A typical `/etc/my.cnf` file might look like this:

    [mysqld]
    datadir=/usr/local/mysql/var
    socket=/var/tmp/mysql.sock
    port=3306
    user=mysql

    [mysql.server]
    basedir=/usr/local/mysql

The mysql.server script understands the following options: `basedir`, `datadir`, and `pid-file`. If specified, they must be placed in an option file, not on the command line. mysql.server understands only `start` and `stop` as command-line arguments.

The following table shows which option groups the server and each startup script read from option files:

Script | Option Groups
mysqld | `[mysqld]`, `[server]`, `[mysqld-`major_version`]`
mysqld_safe | `[mysqld]`, `[server]`, `[mysqld_safe]`
mysql.server | `[mysqld]`, `[mysql.server]`, `[server]`

`[mysqld-`major_version`]` means that groups with names like `[mysqld-4.1]` and `[mysqld-5.0]` are read by servers having versions 4.1.x, 5.0.x, and so forth. This feature can be used to specify options that can be read only by servers within a given release series.

For backward compatibility, mysql.server also reads the `[mysql_server]` group and mysqld_safe also reads the `[safe_mysqld]` group. However, you should update your option files to use the `[mysql.server]` and `[mysqld_safe]` groups instead when using MySQL 5.0.

See Section 4.3.2, “Using Option Files”.

##### 2.4.15.2.3. Starting and Troubleshooting the MySQL Server

This section provides troubleshooting suggestions for problems starting the server on Unix. If you are using Windows, see Section 2.4.8.13, “Troubleshooting a MySQL Installation Under Windows”.

If you have problems starting the server, here are some things to try:

- Check the error log to see why the server does not start.

- Specify any special options needed by the storage engines you are using.

- Make sure that the server knows where to find the data directory.

- Make sure that the server can access the data directory. The ownership and permissions of the data directory and its contents must be set such that the server can read and modify them.

- Verify that the network interfaces the server wants to use are available.

Some storage engines have options that control their behavior. You can create a `my.cnf` file and specify startup options for the engines that you plan to use. If you are going to use storage engines that support transactional tables (`InnoDB`, `BDB`, `NDB`), be sure that you have them configured the way you want before starting the server:

MySQL Enterprise For expert advice on start-up options appropriate to your circumstances, subscribe to The MySQL Network Monitoring and Advisory Service. For more information see, http://www.mysql.com/products/enterprise/advisors.html.

- If you are using `InnoDB` tables, see Section 14.2.3, “`InnoDB` Configuration”.

- If you are using `BDB` (Berkeley DB) tables, see Section 14.5.3, “`BDB` Startup Options”.

- If you are using MySQL Cluster, see Section 15.4, “MySQL Cluster Configuration”.

Storage engines will use default option values if you specify none, but it is recommended that you review the available options and specify explicit values for those for which the defaults are not appropriate for your installation.

When the mysqld server starts, it changes location to the data directory. This is where it expects to find databases and where it expects to write log files. The server also writes the pid (process ID) file in the data directory.

The data directory location is hardwired in when the server is compiled. This is where the server looks for the data directory by default. If the data directory is located somewhere else on your system, the server will not work properly. You can determine what the default path settings are by invoking mysqld with the `--verbose` and `--help` options.

If the default locations don't match the MySQL installation layout on your system, you can override them by specifying options to mysqld or mysqld_safe on the command line or in an option file.

To specify the location of the data directory explicitly, use the `--datadir` option. However, normally you can tell mysqld the location of the base directory under which MySQL is installed and it looks for the data directory there. You can do this with the `--basedir` option.

To check the effect of specifying path options, invoke mysqld with those options followed by the `--verbose` and `--help` options. For example, if you change location into the directory where mysqld is installed and then run the following command, it shows the effect of starting the server with a base directory of `/usr/local`:

    shell> ./mysqld --basedir=/usr/local --verbose --help

You can specify other options such as `--datadir` as well, but `--verbose` and `--help` must be the last options.

Once you determine the path settings you want, start the server without `--verbose` and `--help`.

If mysqld is currently running, you can find out what path settings it is using by executing this command:

    shell> mysqladmin variables

Or:

    shell> mysqladmin -h host_name variables

`host_name` is the name of the MySQL server host.

If you get `Errcode 13` (which means `Permission denied`) when starting mysqld, this means that the privileges of the data directory or its contents do not allow the server access. In this case, you change the permissions for the involved files and directories so that the server has the right to use them. You can also start the server as `root`, but this raises security issues and should be avoided.

On Unix, change location into the data directory and check the ownership of the data directory and its contents to make sure the server has access. For example, if the data directory is `/usr/local/mysql/var`, use this command:

    shell> ls -la /usr/local/mysql/var

If the data directory or its files or subdirectories are not owned by the login account that you use for running the server, change their ownership to that account. If the account is named `mysql`, use these commands:

    shell> chown -R mysql /usr/local/mysql/var
    shell> chgrp -R mysql /usr/local/mysql/var

If the server fails to start up correctly, check the error log. Log files are located in the data directory (typically `C:\Program Files\MySQL\MySQL Server 5.0\data` on Windows, `/usr/local/mysql/data` for a Unix binary distribution, and `/usr/local/var` for a Unix source distribution). Look in the data directory for files with names of the form ``host_name`.err` and ``host_name`.log`, where `host_name` is the name of your server host. Then examine the last few lines of these files. On Unix, you can use `tail` to display them:

    shell> tail host_name.err
    shell> tail host_name.log

The error log should contain information that indicates why the server couldn't start. For example, you might see something like this in the log:

    000729 14:50:10  bdb:  Recovery function for LSN 1 27595 failed
    000729 14:50:10  bdb:  warning: ./test/t1.db: No such file or directory
    000729 14:50:10  Can't init databases

This means that you did not start mysqld with the `--bdb-no-recover` option and Berkeley DB found something wrong with its own log files when it tried to recover your databases. To be able to continue, you should move the old Berkeley DB log files from the database directory to some other place, where you can later examine them. The `BDB` log files are named in sequence beginning with `log.0000000001`, where the number increases over time.

If you are running mysqld with `BDB` table support and mysqld dumps core at startup, this could be due to problems with the `BDB` recovery log. In this case, you can try starting mysqld with `--bdb-no-recover`. If that helps, you should remove all `BDB` log files from the data directory and try starting mysqld again without the `--bdb-no-recover` option.

If either of the following errors occur, it means that some other program (perhaps another mysqld server) is using the TCP/IP port or Unix socket file that mysqld is trying to use:

    Can't start server: Bind on TCP/IP port: Address already in use
    Can't start server: Bind on unix socket...

Use ps to determine whether you have another mysqld server running. If so, shut down the server before starting mysqld again. (If another server is running, and you really want to run multiple servers, you can find information about how to do so in Section 5.13, “Running Multiple MySQL Servers on the Same Machine”.)

If no other server is running, try to execute the command `telnet `your_host_name` `tcp_ip_port_number``. (The default MySQL port number is 3306.) Then press Enter a couple of times. If you don't get an error message like `telnet: Unable to connect to remote host: Connection refused`, some other program is using the TCP/IP port that mysqld is trying to use. You'll need to track down what program this is and disable it, or else tell mysqld to listen to a different port with the `--port` option. In this case, you'll also need to specify the port number for client programs when connecting to the server via TCP/IP.

Another reason the port might be inaccessible is that you have a firewall running that blocks connections to it. If so, modify the firewall settings to allow access to the port.

If the server starts but you can't connect to it, you should make sure that you have an entry in `/etc/hosts` that looks like this:

    127.0.0.1       localhost

This problem occurs only on systems that do not have a working thread library and for which MySQL must be configured to use MIT-pthreads.

If you cannot get mysqld to start, you can try to make a trace file to find the problem by using the `--debug` option. See Section H.1.2, “Creating Trace Files”.

#### 2.4.15.3. Securing the Initial MySQL Accounts

Part of the MySQL installation process is to set up the `mysql` database that contains the grant tables:

- Windows distributions contain preinitialized grant tables that are installed automatically.

- On Unix, the grant tables are populated by the mysql_install_db program. Some installation methods run this program for you. Others require that you execute it manually. For details, see Section 2.4.15.2, “Unix Post-Installation Procedures”.

The grant tables define the initial MySQL user accounts and their access privileges. These accounts are set up as follows:

- Accounts with the username `root` are created. These are superuser accounts that can do anything. The initial `root` account passwords are empty, so anyone can connect to the MySQL server as `root` — without a password — and be granted all privileges.

  - On Windows, one `root` account is created; this account allows connecting from the local host only. The Windows installer will optionally create an account allowing for connections from any host only if the user selects the Enable root access from remote machines option during installation.

  - On Unix, both `root` accounts are for connections from the local host. Connections must be made from the local host by specifying a hostname of `localhost` for one of the accounts, or the actual hostname or IP number for the other.

- Two anonymous-user accounts are created, each with an empty username. The anonymous accounts have no password, so anyone can use them to connect to the MySQL server.

  - On Windows, one anonymous account is for connections from the local host. It has all privileges, just like the `root` accounts. The other is for connections from any host and has all privileges for the `test` database and for other databases with names that start with `test`.

  - On Unix, both anonymous accounts are for connections from the local host. Connections must be made from the local host by specifying a hostname of `localhost` for one of the accounts, or the actual hostname or IP number for the other. These accounts have all privileges for the `test` database and for other databases with names that start with `test_`.

As noted, none of the initial accounts have passwords. This means that your MySQL installation is unprotected until you do something about it:

- If you want to prevent clients from connecting as anonymous users without a password, you should either assign a password to each anonymous account or else remove the accounts.

- You should assign a password to each MySQL `root` account.

The following instructions describe how to set up passwords for the initial MySQL accounts, first for the anonymous accounts and then for the `root` accounts. Replace “`newpwd`” in the examples with the actual password that you want to use. The instructions also cover how to remove the anonymous accounts, should you prefer not to allow anonymous access at all.

You might want to defer setting the passwords until later, so that you don't need to specify them while you perform additional setup or testing. However, be sure to set them before using your installation for production purposes.

Anonymous Account Password Assignment

To assign passwords to the anonymous accounts, connect to the server as `root` and then use either `SET PASSWORD` or `UPDATE`. In either case, be sure to encrypt the password using the `PASSWORD()` function.

To use `SET PASSWORD` on Windows, do this:

    shell> mysql -u root
    mysql> SET PASSWORD FOR ''@'localhost' = PASSWORD('newpwd');
    mysql> SET PASSWORD FOR ''@'%' = PASSWORD('newpwd');

To use `SET PASSWORD` on Unix, do this:

    shell> mysql -u root
    mysql> SET PASSWORD FOR ''@'localhost' = PASSWORD('newpwd');
    mysql> SET PASSWORD FOR ''@'host_name' = PASSWORD('newpwd');

In the second `SET PASSWORD` statement, replace `host_name` with the name of the server host. This is the name that is specified in the `Host` column of the non-`localhost` record for `root` in the `user` table. If you don't know what hostname this is, issue the following statement before using `SET PASSWORD`:

    mysql> SELECT Host, User FROM mysql.user;

Look for the record that has `root` in the `User` column and something other than `localhost` in the `Host` column. Then use that `Host` value in the second `SET PASSWORD` statement.

The other way to assign passwords to the anonymous accounts is by using `UPDATE` to modify the `user` table directly. Connect to the server as `root` and issue an `UPDATE` statement that assigns a value to the `Password` column of the appropriate `user` table records. The procedure is the same for Windows and Unix. The following `UPDATE` statement assigns a password to both anonymous accounts at once:

    shell> mysql -u root
    mysql> UPDATE mysql.user SET Password = PASSWORD('newpwd')
        ->     WHERE User = '';
    mysql> FLUSH PRIVILEGES;

After you update the passwords in the `user` table directly using `UPDATE`, you must tell the server to re-read the grant tables with `FLUSH PRIVILEGES`. Otherwise, the change goes unnoticed until you restart the server.

Anonymous Account Removal

If you prefer to remove the anonymous accounts instead, do so as follows:

    shell> mysql -u root
    mysql> DELETE FROM mysql.user WHERE User = '';
    mysql> FLUSH PRIVILEGES;

The `DELETE` statement applies both to Windows and to Unix. On Windows, if you want to remove only the anonymous account that has the same privileges as `root`, do this instead:

    shell> mysql -u root
    mysql> DELETE FROM mysql.user WHERE Host='localhost' AND User='';
    mysql> FLUSH PRIVILEGES;

That account allows anonymous access but has full privileges, so removing it improves security.

`root` Account Password Assignment

You can assign passwords to the `root` accounts in several ways. The following discussion demonstrates three methods:

- Use the `SET PASSWORD` statement

- Use the mysqladmin command-line client program

- Use the `UPDATE` statement

To assign passwords using `SET PASSWORD`, connect to the server as `root` and issue two `SET PASSWORD` statements. Be sure to encrypt the password using the `PASSWORD()` function.

For Windows, do this:

    shell> mysql -u root
    mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('newpwd');
    mysql> SET PASSWORD FOR 'root'@'%' = PASSWORD('newpwd');

For Unix, do this:

    shell> mysql -u root
    mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('newpwd');
    mysql> SET PASSWORD FOR 'root'@'host_name' = PASSWORD('newpwd');

In the second `SET PASSWORD` statement, replace `host_name` with the name of the server host. This is the same hostname that you used when you assigned the anonymous account passwords.

To assign passwords to the `root` accounts using mysqladmin, execute the following commands:

    shell> mysqladmin -u root password "newpwd"
    shell> mysqladmin -u root -h host_name password "newpwd"

These commands apply both to Windows and to Unix. In the second command, replace `host_name` with the name of the server host. The double quotes around the password are not always necessary, but you should use them if the password contains spaces or other characters that are special to your command interpreter.

You can also use `UPDATE` to modify the `user` table directly. The following `UPDATE` statement assigns a password to both `root` accounts at once:

    shell> mysql -u root
    mysql> UPDATE mysql.user SET Password = PASSWORD('newpwd')
        ->     WHERE User = 'root';
    mysql> FLUSH PRIVILEGES;

The `UPDATE` statement applies both to Windows and to Unix.

After the passwords have been set, you must supply the appropriate password whenever you connect to the server. For example, if you want to use mysqladmin to shut down the server, you can do so using this command:

    shell> mysqladmin -u root -p shutdown
    Enter password: (enter root password here)

Note: If you forget your `root` password after setting it up, Section B.4.1, “How to Reset the Root Password”, covers the procedure for resetting it.

To set up additional accounts, you can use the `GRANT` statement. For instructions, see Section 5.9.2, “Adding New User Accounts to MySQL”.

### 2.4.16. Upgrading MySQL

As a general rule, we recommend that when upgrading from one release series to another, you should go to the next series rather than skipping a series. For example, if you currently are running MySQL 3.23 and wish to upgrade to a newer series, upgrade to MySQL 4.0 rather than to 4.1 or 5.0.

The following items form a checklist of things that you should do whenever you perform an upgrade:

- Before upgrading from MySQL 4.1 to 5.0, read Section 2.4.16.2, “Upgrading from MySQL 4.1 to 5.0”) as well as Appendix G, MySQL Change History. These provide information about features that are new in MySQL 5.0 or differ from those found in MySQL 4.1. If you wish to upgrade from a release series previous to MySQL 4.1, you should upgrade to each successive release series in turn until you have reached MySQL 4.1, and then proceed with the upgrade to MySQL 5.0. For information on upgrading from MySQL 4.1 or earlier releases, see the MySQL 3.23, 4.0, 4.1 Reference Manual.

- Before you perform an upgrade, back up your databases, including the `mysql` database that contains the grant tables.

- Some releases of MySQL introduce incompatible changes to tables. (Our aim is to avoid these changes, but occasionally they are necessary to correct problems that would be worse than an incompatibility between releases.) Some releases of MySQL introduce changes to the structure of the grant tables to add new privileges or features.

  To avoid problems due to such changes, after you upgrade to a new version of MySQL, you should run mysql_upgrade to check your tables (and repair them if necessary), and to update your grant tables to make sure that they have the current structure so that you can take advantage of any new capabilities. See Section 5.6.3, “mysql_upgrade — Check Tables for MySQL Upgrade”.

- If you are running MySQL Server on Windows, see Section 2.4.8.14, “Upgrading MySQL on Windows”.

- If you are using replication, see Section 6.6, “Upgrading a Replication Setup”, for information on upgrading your replication setup.

- If you previously installed a MySQL-Max distribution that includes a server named mysqld-max, and then upgrade later to a non-Max version of MySQL, mysqld_safe still attempts to run the old mysqld-max server. If you perform such an upgrade, you should remove the old mysqld-max server manually to ensure that mysqld_safe runs the new mysqld server.

- If you have created a user-defined function (UDF) with a given name and upgrade MySQL to a version that implements a new built-in function with the same name, the UDF becomes inaccessible. To correct this, use `DROP FUNCTION` to drop the UDF, and then use `CREATE FUNCTION` to re-create the UDF with a different non-conflicting name. If a new version of MySQL implements a built-in function with the same name as an existing stored function, you have two choices: Rename the stored function to use a non-conflicting name, or change calls to the function so that they use a database qualifier (that is, use ``db_name`.`func_name`()` syntax). See Section 9.2.3, “Function Name Parsing and Resolution”, for the rules describing how the server interprets references to different kinds of functions.

You can always move the MySQL format files and data files between different versions on the same architecture as long as you stay within versions for the same release series of MySQL. If you change the character set when running MySQL, you must run myisamchk -r -q --set-collation=`collation_name` on all `MyISAM` tables. Otherwise, your indexes may not be ordered correctly, because changing the character set may also change the sort order.

If you are cautious about using new versions, you can always rename your old mysqld before installing a newer one. For example, if you are using MySQL 4.1.13 and want to upgrade to 5.0.10, rename your current server from mysqld to mysqld-4.1.13. If your new mysqld then does something unexpected, you can simply shut it down and restart with your old mysqld.

If, after an upgrade, you experience problems with recompiled client programs, such as `Commands out of sync` or unexpected core dumps, you probably have used old header or library files when compiling your programs. In this case, you should check the date for your `mysql.h` file and `libmysqlclient.a` library to verify that they are from the new MySQL distribution. If not, recompile your programs with the new headers and libraries.

If problems occur, such as that the new mysqld server does not start or that you cannot connect without a password, verify that you do not have an old `my.cnf` file from your previous installation. You can check this with the `--print-defaults` option (for example, mysqld --print-defaults). If this command displays anything other than the program name, you have an active `my.cnf` file that affects server or client operation.

It is a good idea to rebuild and reinstall the Perl `DBD::mysql` module whenever you install a new release of MySQL. The same applies to other MySQL interfaces as well, such as the PHP `mysql` extension and the Python `MySQLdb` module.

#### 2.4.16.1. Upgrading from MySQL 5.0 to 5.1

This section does not apply to MySQL Enterprise Server users.

When upgrading a 5.0 installation to 5.0.10 or above note that it is necessary to upgrade your grant tables. Otherwise, creating stored procedures and functions might not work. The procedure for doing this is described in Section 5.6.3, “mysql_upgrade — Check Tables for MySQL Upgrade”.

#### 2.4.16.2. Upgrading from MySQL 4.1 to 5.0

Note: It is good practice to back up your data before installing any new version of software. Although MySQL works very hard to ensure a high level of quality, you should protect your data by making a backup. MySQL recommends that you dump and reload your tables from any previous version to upgrade to 5.0.

In general, you should do the following when upgrading from MySQL 4.1 from 5.0:

- Check the items in Section 2.4.16, “Upgrading MySQL”, to see whether any of them might affect your applications.

- Check the items in the change lists found later in this section to see whether any of them might affect your applications. Note particularly any that are marked Incompatible change. These result in incompatibilities with earlier versions of MySQL, and may require your attention before you upgrade.

- Some releases of MySQL introduce incompatible changes to tables. (Our aim is to avoid these changes, but occasionally they are necessary to correct problems that would be worse than an incompatibility between releases.) Some releases of MySQL introduce changes to the structure of the grant tables to add new privileges or features.

  To avoid problems due to such changes, after you upgrade to a new version of MySQL, you should check your tables (and repair them if necessary), and update your grant tables to make sure that they have the current structure so that you can take advantage of any new capabilities. See Section 5.6.3, “mysql_upgrade — Check Tables for MySQL Upgrade”.

- Read the MySQL 5.0 change history to see what significant new features you can use in 5.0. See Section G.1, “Changes in release 5.0.x (Production)”.

- If you are running MySQL Server on Windows, see Section 2.4.8.14, “Upgrading MySQL on Windows”.

- MySQL 5.0 adds support for stored procedures. This support requires the `mysql.proc` table. To create this table, you should run the mysql_upgrade program as described in Section 5.6.3, “mysql_upgrade — Check Tables for MySQL Upgrade”.

- MySQL 5.0 adds support for views. This support requires extra privilege columns in the `mysql.user` and `mysql.db` tables. To create these columns, you should run the mysql_upgrade program as described in Section 5.6.3, “mysql_upgrade — Check Tables for MySQL Upgrade”.

- If you are using replication, see Section 6.6, “Upgrading a Replication Setup”, for information on upgrading your replication setup.

Several visible behaviors have changed between MySQL 4.1 and MySQL 5.0 to make MySQL more compatible with standard SQL. These changes may affect your applications.

The following lists describe changes that may affect applications and that you should watch out for when upgrading to MySQL 5.0.

Server Changes:

- Incompatible change: The indexing order for end-space in `TEXT` columns for `InnoDB` and `MyISAM` tables has changed. Starting from 5.0.3, `TEXT` indexes are compared as space-padded at the end (just as MySQL sorts `CHAR`, `VARCHAR` and `TEXT` fields). If you have a index on a `TEXT` column, you should run `CHECK TABLE` on it. If the check reports errors, rebuild the indexes: Dump and reload the table if it is an `InnoDB` table, or run `OPTIMIZE TABLE` or `REPAIR TABLE` if it is a `MyISAM` table.

- Warning: Incompatible change. For `BINARY` columns, the pad value and how it is handled has changed as of MySQL 5.0.15. The pad value for inserts now is `0x00` rather than space, and there is no stripping of the pad value for retrievals. For details, see Section 11.4.2, “The `BINARY` and `VARBINARY` Types”.

- Incompatible change: As of MySQL 5.0.3, the server by default no longer loads user-defined functions (UDFs) unless they have at least one auxiliary symbol (for example, an `xxx_init` or `xxx_deinit` symbol) defined in addition to the main function symbol. This behavior can be overridden with the `--allow-suspicious-udfs` option. See Section 24.2.4.6, “User-Defined Function Security Precautions”.

- Incompatible change: The update log has been removed in MySQL 5.0. If you had enabled it previously, you should enable the binary log instead.

- Incompatible change: Support for the `ISAM` storage engine has been removed in MySQL 5.0. If you have any `ISAM` tables, you should convert them before upgrading. For example, to convert an `ISAM` table to use the `MyISAM` storage engine, use this statement:

      ALTER TABLE tbl_name ENGINE = MyISAM;

  Use a similar statement for every `ISAM` table in each of your databases.

- Incompatible change: Support for `RAID` options in `MyISAM` tables has been removed in MySQL 5.0. If you have tables that use these options, you should convert them before upgrading. One way to do this is to dump them with mysqldump, edit the dump file to remove the `RAID` options in the `CREATE TABLE` statements, and reload the dump file. Another possibility is to use `CREATE TABLE `new_tbl` ... SELECT `raid_tbl`` to create a new table from the `RAID` table. However, the `CREATE TABLE` part of the statement must contain sufficient information to re-create column attributes as well as indexes, or column attributes may be lost and indexes will not appear in the new table. See Section 13.1.5, “`CREATE TABLE` Syntax”.

  The `.MYD` files for `RAID` tables in a given database are stored under the database directory in subdirectories that have names consisting of two hex digits in the range from `00` to `ff`. After converting all tables that use `RAID` options, these `RAID`-related subdirectories still will exist but can be removed. Verify that they are empty, and then remove them manually. (If they are not empty, there is some `RAID` table that has not been converted.)

- As of MySQL 5.0.25, the `lc_time_names` system variable specifies the locale that controls the language used to display day and month names and abbreviations. This variable affects the output from the `DATE_FORMAT()`, `DAYNAME()` and `MONTHNAME()` functions. See Section 5.11.9, “MySQL Server Locale Support”.

- In MySQL 5.0.6, binary logging of stored routines and triggers was changed. This change has implications for security, replication, and data recovery, as discussed in Section 17.4, “Binary Logging of Stored Routines and Triggers”.

SQL Changes:

- Incompatible change: Beginning with MySQL 5.0.12, natural joins and joins with `USING`, including outer join variants, are processed according to the SQL:2003 standard. The changes include elimination of redundant output columns for `NATURAL` joins and joins specified with a `USING` clause and proper ordering of output columns. The precedence of the comma operator also now is lower compared to `JOIN`, `LEFT JOIN`, and so forth.

  These changes make MySQL more compliant with standard SQL. However, they can result in different output columns for some joins. Also, some queries that appeared to work correctly prior to 5.0.12 must be rewritten to comply with the standard. For details about the scope of the changes and examples that show what query rewrites are necessary, see Section 13.2.7.1, “`JOIN` Syntax”.

- Incompatible change: Previously, a lock wait timeout caused `InnoDB` to roll back the entire current transaction. As of MySQL 5.0.13, it rolls back only the most recent SQL statement.

- Incompatible change: The namespace for triggers has changed in MySQL 5.0.10. Previously, trigger names had to be unique per table. Now they must be unique within the schema (database). An implication of this change is that `DROP TRIGGER` syntax now uses a schema name instead of a table name (schema name is optional and, if omitted, the current schema will be used).

  When upgrading from a previous version of MySQL 5 to MySQL 5.0.10 or newer, you must drop all triggers and re-create them or `DROP TRIGGER` will not work after the upgrade. Here is a suggested procedure for doing this:

  1. Upgrade to MySQL 5.0.10 or later to be able to access trigger information in the `INFORMATION_SCHEMA.TRIGGERS` table. (It should work even for pre-5.0.10 triggers.)

  2. Dump all trigger definitions using the following `SELECT` statement:

         SELECT CONCAT('CREATE TRIGGER ', t.TRIGGER_SCHEMA, '.', t.TRIGGER_NAME,
                       ' ', t.ACTION_TIMING, ' ', t.EVENT_MANIPULATION, ' ON ',
                       t.EVENT_OBJECT_SCHEMA, '.', t.EVENT_OBJECT_TABLE,
                       ' FOR EACH ROW ', t.ACTION_STATEMENT, '//' )
         INTO OUTFILE '/tmp/triggers.sql'
         FROM INFORMATION_SCHEMA.TRIGGERS AS t;

     The statement uses `INTO OUTFILE`, so you must have the `FILE` privilege. The file will be created on the server host. Use a different filename if you like. To be 100% safe, inspect the trigger definitions in the `triggers.sql` file, and perhaps make a backup of the file.

  3. Stop the server and drop all triggers by removing all `.TRG` files in your database directories. Change location to your data directory and issue this command:

         shell> rm */*.TRG

  4. Start the server and re-create all triggers using the `triggers.sql` file. For the file created earlier, use these commands in the mysql program:

         mysql> delimiter // ;
         mysql> source /tmp/triggers.sql //

  5. Use the `SHOW TRIGGERS` statement to check that all triggers were created successfully.

- Incompatible change: As of MySQL 5.0.15, the `CHAR()` function returns a binary string rather than a string in the connection character set. An optional `USING `charset_name`` clause may be used to produce a result in a specific character set instead. Also, arguments larger than 256 produce multiple characters. They are no longer interpreted modulo 256 to produce a single character each. These changes may cause some incompatibilities:

  - `CHAR(ORD('A')) = 'a'` is no longer true:

        mysql> SELECT CHAR(ORD('A')) = 'a';
        +----------------------+
        | CHAR(ORD('A')) = 'a' |
        +----------------------+
        |                    0 |
        +----------------------+

    To perform a case-insensitive comparison, you can produce a result string in a non-binary character set by adding a `USING` clause or converting the result:

        mysql> SELECT CHAR(ORD('A') USING latin1) = 'a';
        +-----------------------------------+
        | CHAR(ORD('A') USING latin1) = 'a' |
        +-----------------------------------+
        |                                 1 |
        +-----------------------------------+
        mysql> SELECT CONVERT(CHAR(ORD('A')) USING latin1) = 'a';
        +--------------------------------------------+
        | CONVERT(CHAR(ORD('A')) USING latin1) = 'a' |
        +--------------------------------------------+
        |                                          1 |
        +--------------------------------------------+

  - `CREATE TABLE ... SELECT CHAR(...)` produces a `VARBINARY` column, not a `VARCHAR` column. To produce a `VARCHAR` column, use `USING` or `CONVERT()` as just described to convert the `CHAR()` result into a non-binary character set.

  - Previously, the following statements inserted the value `0x00410041` (`'AA'` as a `ucs2` string) into the table:

        CREATE TABLE t (ucs2_column CHAR(2) CHARACTER SET ucs2);
        INSERT INTO t VALUES (CHAR(0x41,0x41));

    As of MySQL 5.0.15, the statements insert a single `ucs2` character with value `0x4141`.

- Incompatible change: By default, integer subtraction involving an unsigned value should produce an unsigned result. Tracking of the “unsignedness” of an expression was improved in MySQL 5.0.13. This means that, in some cases where an unsigned subtraction would have resulted in a signed integer, it now results in an unsigned integer. One context in which this difference manifests itself is when a subtraction involving an unsigned operand would be negative.

  Suppose that `i` is a `TINYINT UNSIGNED` column and has a value of 0. The server evaluates the following expression using 64-bit unsigned integer arithmetic with the following result:

      mysql> SELECT i - 1 FROM t;
      +----------------------+
      | i - 1                |
      +----------------------+
      | 18446744073709551615 |
      +----------------------+

  If the expression is used in an `UPDATE t SET i = i - 1` statement, the expression is evaluated and the result assigned to `i` according to the usual rules for handling values outside the column range or 0 to 255. That is, the value is clipped to the nearest endpoint of the range. However, the result is version-specific:

  - Before MySQL 5.0.13, the expression is evaluated but is treated as the equivalent 64-bit signed value (–1) for the assignment. The value of –1 is clipped to the nearest endpoint of the column range, resulting in a value of 0:

        mysql> UPDATE t SET i = i - 1; SELECT i FROM t;
        +------+
        | i    |
        +------+
        |    0 |
        +------+

  - As of MySQL 5.0.13, the expression is evaluated and retains its unsigned attribute for the assignment. The value of 18446744073709551615 is clipped to the nearest endpoint of the column range, resulting in a value of 255:

        mysql> UPDATE t SET i = i - 1; SELECT i FROM t;
        +------+
        | i    |
        +------+
        |  255 |
        +------+

  To get the older behavior, use `CAST()` to convert the expression result to a signed value:

      UPDATE t SET i = CAST(i - 1 AS SIGNED);

  Alternatively, set the `NO_UNSIGNED_SUBTRACTION` SQL mode. However, this will affect all integer subtractions involving unsigned values.

- Incompatible change: Before MySQL 5.0.13, `NOW()` and `SYSDATE()` return the same value (the time at which the statement in which the function occurs begins executing). As of MySQL 5.0.13, `SYSDATE()` returns the time at which it it executes, which can differ from the value returned by `NOW()`. For information about the implications for binary logging and replication, see the description for `SYSDATE()` in Section 12.5, “Date and Time Functions” and for `SET TIMESTAMP` in Section 13.5.3, “`SET` Syntax”. To restore the former behavior for `SYSDATE()` and cause it to be an alias for `NOW()`, start the server with the `--sysdate-is-now` option (available as of MySQL 5.0.20).

- Incompatible change: Before MySQL 5.0.13, `GREATEST(`x`,NULL)` and `LEAST(`x`,NULL)` return `x` when `x` is a non-`NULL` value. As of 5.0.3, both functions return `NULL` if any argument is `NULL`, the same as Oracle. This change can cause problems for applications that rely on the old behavior.

- Incompatible change: Before MySQL 4.1.13/5.0.8, conversion of `DATETIME` values to numeric form by adding zero produced a result in `YYYYMMDDHHMMSS` format. The result of `DATETIME+0` is now in `YYYYMMDDHHMMSS.000000` format.

- Incompatible change: In MySQL 4.1.12/5.0.6, the behavior of `LOAD DATA INFILE` and `SELECT ... INTO OUTFILE` has changed when the `FIELDS TERMINATED BY` and `FIELDS ENCLOSED BY` values both are empty. Formerly, a column was read or written the display width of the column. For example, `INT(4)` was read or written using a field with a width of 4. Now columns are read and written using a field width wide enough to hold all values in the field. However, data files written before this change was made might not be reloaded correctly with `LOAD DATA INFILE` for MySQL 4.1.12/5.0.6 and up. This change also affects data files read by mysqlimport and written by mysqldump --tab, which use `LOAD DATA INFILE` and `SELECT ... INTO OUTFILE`. For more information, see Section 13.2.5, “`LOAD DATA INFILE` Syntax”.

- Incompatible change: The implementation of `DECIMAL` has changed in MySQL 5.0.3. You should make your applications aware of this change. For information about this change, and about possible incompatibilities with old applications, see Chapter 21, Precision Math.

  `DECIMAL` columns are stored in a more efficient format. To convert a table to use the new `DECIMAL` type, you should do an `ALTER TABLE` on it. (The `ALTER TABLE` also will change the table's `VARCHAR` columns to use the new `VARCHAR` data type properties, described in a separate item.)

  A consequence of the change in handling of the `DECIMAL` and `NUMERIC` fixed-point data types is that the server is more strict to follow standard SQL. For example, a data type of `DECIMAL(3,1)` stores a maximum value of 99.9. Before MySQL 5.0.3, the server allowed larger numbers to be stored. That is, it stored a value such as 100.0 as 100.0. As of MySQL 5.0.3, the server clips 100.0 to the maximum allowable value of 99.9. If you have tables that were created before MySQL 5.0.3 and that contain floating-point data not strictly legal for the data type, you should alter the data types of those columns. For example:

      ALTER TABLE tbl_name MODIFY col_name DECIMAL(4,1);

  The behavior used by the server for `DECIMAL` columns in a table depends on the version of MySQL used to create the table. If your server is from MySQL 5.0.3 or higher, but you have `DECIMAL` columns in tables that were created before 5.0.3, the old behavior still applies to those columns. To convert the tables to the newer `DECIMAL` format, dump them with mysqldump and reload them.

- Incompatible change: MySQL 5.0.3 and up uses precision math when calculating with `DECIMAL` and integer columns (64 decimal digits) and for rounding exact-value numbers. Rounding behavior is well-defined, not dependent on the implementation of the underlying C library. However, this might result in incompatibilities for applications that rely on the old behavior. (For example, inserting .5 into an `INT` column results in 1 as of MySQL 5.0.3, but might be 0 in older versions.) For more information about rounding behavior, see Section 21.4, “Rounding Behavior”, and Section 21.5, “Precision Math Examples”.

- Incompatible change: `MyISAM` and `InnoDB` tables created with `DECIMAL` columns in MySQL 5.0.3 to 5.0.5 will appear corrupt after an upgrade to MySQL 5.0.6. (The same incompatibility will occur for these tables created in MySQL 5.0.6 after a downgrade to MySQL 5.0.3 to 5.0.5.) If you have such tables, check and repair them with mysql_upgrade after upgrading. See Section 5.6.3, “mysql_upgrade — Check Tables for MySQL Upgrade”.

- Warning: Incompatible change: For user-defined functions, exact-value decimal arguments such as `1.3` or `DECIMAL` column values were passed as `REAL_RESULT` values prior to MySQL 5.0.3. As of 5.0.3, they are passed as strings with a type of `DECIMAL_RESULT`. If you upgrade to 5.0.3 and find that your UDF now receives string values, use the initialization function to coerce the arguments to numbers as described in Section 24.2.4.3, “UDF Argument Processing”.

- Incompatible change: Before MySQL 5.0.2, `SHOW STATUS` returned global status values. The default as of 5.0.2 is to return session values, which is incompatible with previous versions. To issue a `SHOW STATUS` statement that will retrieve global status values for all versions of MySQL, write it like this:

      SHOW /*!50002 GLOBAL */ STATUS;

- Incompatible change: User variables are not case sensitive in MySQL 5.0. In MySQL 4.1, `SET @x = 0; SET @X = 1; SELECT @x;` created two variables and returned `0`. In MySQL 5.0, it creates one variable and returns `1`. Replication setups that rely on the old behavior may be affected by this change.

- Some keywords are reserved in MySQL 5.0 that were not reserved in MySQL 4.1. See Section 9.3, “Reserved Words”.

- The `LOAD DATA FROM MASTER` and `LOAD TABLE FROM MASTER` statements are deprecated. See Section 13.6.2.2, “`LOAD DATA FROM MASTER` Syntax”, for recommended alternatives.

- As of MySQL 5.0.3, trailing spaces no longer are removed from values stored in `VARCHAR` and `VARBINARY` columns. The maximum lengths for `VARCHAR` and `VARBINARY` columns in MySQL 5.0.3 and later are 65,535 characters and 65,535 bytes, respectively.

  When a binary upgrade (filesystem-level copy of data files) to MySQL 5.0 is performed for a table with a `VARBINARY` column, the column is space-padded to the full allowable width of the column. This causes values in `VARBINARY` columns that do not occupy the full width of the column to include extra trailing spaces after the upgrade, which means that the data in the column is different.

  In addition, new rows inserted into a table upgraded in this way will be space padded to the full width of the column.

  This issue can be resolved as follows:

  1. For each table containing `VARBINARY` columns, execute the statement

         ALTER TABLE table_name ENGINE=engine_name;

     where `table_name` is the name of the table and `engine_name` is the name of the storage engine currently used by `table_name`. In other words, if the table named `mytable` uses the `MyISAM` storage engine, then you would use this statement:

         ALTER TABLE mytable ENGINE=MYISAM;

     This rebuilds the table so that it uses the 5.0 `VARBINARY` format.

  2. Then you must remove all trailing spaces from any `VARBINARY` column values. For each `VARBINARY` column `varbinary_column`, you should perform the following statement (where `table_name` is the name of the table containing the `VARBINARY` column):

         UPDATE table_name SET varbinary_column = RTRIM(varbinary_column);

     This is necessary and safe because trailing spaces are stripped before 5.0.3, meaning that any trailing spaces are erroneous.

  This problem does not occur (and thus these two steps are not required) for tables upgraded using the recommended procedure of dumping tables prior to the upgrade and reloading them afterwards.

  Note: If you create a table with new `VARCHAR` or `VARBINARY` columns in MySQL 5.0.3 or later, the table will not be usable if you downgrade to a version older than 5.0.3. Dump the table with mysqldump before downgrading and reload it after downgrading.

- Comparisons made between `FLOAT` or `DOUBLE` values that happened to work in MySQL 4.1 may not do so in 5.0. Values of these types are imprecise in all MySQL versions, and you are strongly advised to avoid such comparisons as `WHERE `col_name`=`some_double``, regardless of the MySQL version you are using. See Section B.5.8, “Problems with Floating-Point Comparisons”.

- As of MySQL 5.0.3, `BIT` is a separate data type, not a synonym for `TINYINT(1)`. See Section 11.1.1, “Overview of Numeric Types”.

- MySQL 5.0.2 adds several SQL modes that allow stricter control over rejecting records that have invalid or missing values. See Section 5.2.6, “SQL Modes”, and Section 1.9.6.2, “Constraints on Invalid Data”. If you want to enable this control but continue to use MySQL's capability for storing incorrect dates such as `'2004-02-31'`, you should start the server with `--sql_mode="TRADITIONAL,ALLOW_INVALID_DATES"`.

- As of MySQL 5.0.2, the `SCHEMA` and `SCHEMAS` keywords are accepted as synonyms for `DATABASE` and `DATABASES`, respectively. (While “schemata” is grammatically correct and even appears in some MySQL 5.0 system database and table names, it cannot be used as a keyword.)

- As of MySQL 5.0.25, `TIMESTAMP` columns that are `NOT NULL` now are reported that way by `SHOW COLUMNS` and `INFORMATION_SCHEMA`, rather than as `NULL`.

- A new startup option named `innodb_table_locks` was added that causes `LOCK TABLE` to also acquire `InnoDB` table locks. This option is enabled by default. This can cause deadlocks in applications that use `AUTOCOMMIT=1` and `LOCK TABLES`. If your application encounters deadlocks after upgrading, you may need to add `innodb_table_locks=0` to your `my.cnf` file.

C API Changes:

- Incompatible change: Because the MySQL 5.0 server has a new implementation of the `DECIMAL` data type, a problem may occur if the server is used by older clients that still are linked against MySQL 4.1 client libraries. If a client uses the binary client/server protocol to execute prepared statements that generate result sets containing numeric values, an error will be raised: `'Using unsupported buffer type: 246'`

  This error occurs because the 4.1 client libraries do not support the new `MYSQL_TYPE_NEWDECIMAL` type value added in 5.0. There is no way to disable the new `DECIMAL` data type on the server side. You can avoid the problem by relinking the application with the client libraries from MySQL 5.0.

- Incompatible change: The `ER_WARN_DATA_TRUNCATED` warning symbol was renamed to `WARN_DATA_TRUNCATED` in MySQL 5.0.3.

- The `reconnect` flag in the `MYSQL` structure is set to 0 by `mysql_real_connect()`. Only those client programs which did not explicitly set this flag to 0 or 1 after `mysql_real_connect()` experience a change. Having automatic reconnection enabled by default was considered too dangerous (due to the fact that table locks, temporary tables, user variables, and session variables are lost after reconnection).

#### 2.4.16.3. Copying MySQL Databases to Another Machine

You can copy the `.frm`, `.MYI`, and `.MYD` files for `MyISAM` tables between different architectures that support the same floating-point format. (MySQL takes care of any byte-swapping issues.) See Section 14.1, “The `MyISAM` Storage Engine”.

In cases where you need to transfer databases between different architectures, you can use mysqldump to create a file containing SQL statements. You can then transfer the file to the other machine and feed it as input to the mysql client.

Use mysqldump --help to see what options are available. If you are moving the data to a newer version of MySQL, you should use mysqldump --opt to take advantage of any optimizations that result in a dump file that is smaller and can be processed more quickly.

The easiest (although not the fastest) way to move a database between two machines is to run the following commands on the machine on which the database is located:

    shell> mysqladmin -h 'other_hostname' create db_name
    shell> mysqldump --opt db_name | mysql -h 'other_hostname' db_name

If you want to copy a database from a remote machine over a slow network, you can use these commands:

    shell> mysqladmin create db_name
    shell> mysqldump -h 'other_hostname' --opt --compress db_name | mysql db_name

You can also store the dump in a file, transfer the file to the target machine, and then load the file into the database there. For example, you can dump a database to a compressed file on the source machine like this:

    shell> mysqldump --quick db_name | gzip > db_name.gz

Transfer the file containing the database contents to the target machine and run these commands there:

    shell> mysqladmin create db_name
    shell> gunzip < db_name.gz | mysql db_name

You can also use mysqldump and mysqlimport to transfer the database. For large tables, this is much faster than simply using mysqldump. In the following commands, `DUMPDIR` represents the full pathname of the directory you use to store the output from mysqldump.

First, create the directory for the output files and dump the database:

    shell> mkdir DUMPDIR
    shell> mysqldump --tab=DUMPDIR db_name

Then transfer the files in the `DUMPDIR` directory to some corresponding directory on the target machine and load the files into MySQL there:

    shell> mysqladmin create db_name           # create database
    shell> cat DUMPDIR/*.sql | mysql db_name   # create tables in database
    shell> mysqlimport db_name DUMPDIR/*.txt   # load data into tables

Do not forget to copy the `mysql` database because that is where the grant tables are stored. You might have to run commands as the MySQL `root` user on the new machine until you have the `mysql` database in place.

After you import the `mysql` database on the new machine, execute mysqladmin flush-privileges so that the server reloads the grant table information.

### 2.4.17. Downgrading MySQL

This section does not apply to MySQL Enterprise Server users.

This section describes what you should do to downgrade to an older MySQL version in the unlikely case that the previous version worked better than the new one.

If you are downgrading within the same release series (for example, from 4.1.13 to 4.1.12) the general rule is that you just have to install the new binaries on top of the old ones. There is no need to do anything with the databases. As always, however, it is always a good idea to make a backup.

The following items form a checklist of things you should do whenever you perform a downgrade:

- Read the upgrading section for the release series from which you are downgrading to be sure that it does not have any features you really need. Section 2.4.16, “Upgrading MySQL”.

- If there is a downgrading section for that version, you should read that as well.

In most cases, you can move the MySQL format files and data files between different versions on the same architecture as long as you stay within versions for the same release series of MySQL.

If you downgrade from one release series to another, there may be incompatibilities in table storage formats. In this case, you can use mysqldump to dump your tables before downgrading. After downgrading, reload the dump file using mysql or `mysqlimport` to re-create your tables. For examples, see Section 2.4.16.3, “Copying MySQL Databases to Another Machine”.

The normal symptom of a downward-incompatible table format change when you downgrade is that you can't open tables. In that case, use the following procedure:

1. Stop the older MySQL server that you are downgrading to.

2. Restart the newer MySQL server you are downgrading from.

3. Dump any tables that were inaccessible to the older server by using mysqldump to create a dump file.

4. Stop the newer MySQL server and restart the older one.

5. Reload the dump file into the older server. Your tables should be accessible.

#### 2.4.17.1. Downgrading to MySQL 4.1

This section does not apply to MySQL Enterprise Server users.

MySQL 4.1 does not support stored routines or triggers. If your databases contain stored routines or triggers, prevent them from being dumped when you use mysqldump by using the `--skip-routines` and `--skip-triggers` options. (See Section 8.13, “mysqldump — A Database Backup Program”.)

MySQL 4.1 does not support views. If your databases contain views, remove them with `DROP VIEW` before using mysqldump. (See Section 19.3, “`DROP VIEW` Syntax”.)

After downgrading from MySQL 5.0, you may see the following information in the `mysql.err` file:

    Incorrect information in file: './mysql/user.frm'

In this case, you can do the following:

1. Start MySQL 5.0.4 (or newer).

2. Run mysql_fix_privilege_tables, which will change the `mysql.user` table to a format that both MySQL 4.1 and 5.0 can use.

3. Stop the MySQL server.

4. Start MySQL 4.1.

If the preceding procedure fails, you should be able to do the following instead:

1. Start MySQL 5.0.4 (or newer).

2. Run mysqldump --opt --add-drop-table mysql > /tmp/mysql.dump.

3. Stop the MySQL server.

4. Start MySQL 4.1 with the `--skip-grant` option.

5. Run mysql mysql < /tmp/mysql.dump.

6. Run mysqladmin flush-privileges.

### 2.4.18. Operating System-Specific Notes

#### 2.4.18.1. Linux Notes

This section discusses issues that have been found to occur on Linux. The first few subsections describe general operating system-related issues, problems that can occur when using binary or source distributions, and post-installation issues. The remaining subsections discuss problems that occur with Linux on specific platforms.

Note that most of these problems occur on older versions of Linux. If you are running a recent version, you may see none of them.

##### 2.4.18.1.1. Linux Operating System Notes

MySQL needs at least Linux version 2.0.

Warning: We have seen some strange problems with Linux 2.2.14 and MySQL on SMP systems. We also have reports from some MySQL users that they have encountered serious stability problems using MySQL with kernel 2.2.14. If you are using this kernel, you should upgrade to 2.2.19 (or newer) or to a 2.4 kernel. If you have a multiple-CPU box, you should seriously consider using 2.4 because it gives you a significant speed boost. Your system should be more stable.

When using LinuxThreads, you should see a minimum of three mysqld processes running. These are in fact threads. There is one thread for the LinuxThreads manager, one thread to handle connections, and one thread to handle alarms and signals.

##### 2.4.18.1.2. Linux Binary Distribution Notes

The Linux-Intel binary and RPM releases of MySQL are configured for the highest possible speed. We are always trying to use the fastest stable compiler available.

The binary release is linked with `-static`, which means you do not normally need to worry about which version of the system libraries you have. You need not install LinuxThreads, either. A program linked with `-static` is slightly larger than a dynamically linked program, but also slightly faster (3-5%). However, one problem with a statically linked program is that you can't use user-defined functions (UDFs). If you are going to write or use UDFs (this is something for C or C++ programmers only), you must compile MySQL yourself using dynamic linking.

A known issue with binary distributions is that on older Linux systems that use `libc` (such as Red Hat 4.x or Slackware), you get some (non-fatal) issues with hostname resolution. If your system uses `libc` rather than `glibc2`, you probably will encounter some difficulties with hostname resolution and `getpwnam()`. This happens because `glibc` (unfortunately) depends on some external libraries to implement hostname resolution and `getpwent()`, even when compiled with `-static`. These problems manifest themselves in two ways:

- You may see the following error message when you run mysql_install_db:

      Sorry, the host 'xxxx' could not be looked up

  You can deal with this by executing mysql_install_db --force, which does not execute the resolveip test in mysql_install_db. The downside is that you cannot use hostnames in the grant tables: except for `localhost`, you must use IP numbers instead. If you are using an old version of MySQL that does not support `--force`, you must manually remove the `resolveip` test in `mysql_install` using a text editor.

- You also may see the following error when you try to run mysqld with the `--user` option:

      getpwnam: No such file or directory

  To work around this problem, start mysqld by using the `su` command rather than by specifying the `--user` option. This causes the system itself to change the user ID of the mysqld process so that mysqld need not do so.

Another solution, which solves both problems, is not to use a binary distribution. Obtain a MySQL source distribution (in RPM or `tar.gz` format) and install that instead.

On some Linux 2.2 versions, you may get the error `Resource temporarily unavailable` when clients make a great many new connections to a mysqld server over TCP/IP. The problem is that Linux has a delay between the time that you close a TCP/IP socket and the time that the system actually frees it. There is room for only a finite number of TCP/IP slots, so you encounter the resource-unavailable error if clients attempt too many new TCP/IP connections over a short period of time. For example, you may see the error when you run the MySQL `test-connect` benchmark over TCP/IP.

We have inquired about this problem a few times on different Linux mailing lists but have never been able to find a suitable resolution. The only known “fix” is for clients to use persistent connections, or, if you are running the database server and clients on the same machine, to use Unix socket file connections rather than TCP/IP connections.

##### 2.4.18.1.3. Linux Source Distribution Notes

This section does not apply to MySQL Enterprise Server users.

The following notes regarding `glibc` apply only to the situation when you build MySQL yourself. If you are running Linux on an x86 machine, in most cases it is much better for you to use our binary. We link our binaries against the best patched version of `glibc` we can find and with the best compiler options, in an attempt to make it suitable for a high-load server. For a typical user, even for setups with a lot of concurrent connections or tables exceeding the 2GB limit, our binary is the best choice in most cases. After reading the following text, if you are in doubt about what to do, try our binary first to determine whether it meets your needs. If you discover that it is not good enough, you may want to try your own build. In that case, we would appreciate a note about it so that we can build a better binary next time.

MySQL uses LinuxThreads on Linux. If you are using an old Linux version that doesn't have `glibc2`, you must install LinuxThreads before trying to compile MySQL. You can obtain LinuxThreads from http://dev.mysql.com/downloads/os-linux.html.

Note that `glibc` versions before and including version 2.1.1 have a fatal bug in `pthread_mutex_timedwait()` handling, which is used when `INSERT DELAYED` statements are issued. We recommend that you not use `INSERT DELAYED` before upgrading `glibc`.

Note that Linux kernel and the LinuxThread library can by default handle a maximum of 1,024 threads. If you plan to have more than 1,000 concurrent connections, you need to make some changes to LinuxThreads, as follows:

- Increase `PTHREAD_THREADS_MAX` in `sysdeps/unix/sysv/linux/bits/local_lim.h` to 4096 and decrease `STACK_SIZE` in `linuxthreads/internals.h` to 256KB. The paths are relative to the root of `glibc`. (Note that MySQL is not stable with 600-1000 connections if `STACK_SIZE` is the default of 2MB.)

- Recompile LinuxThreads to produce a new `libpthread.a` library, and relink MySQL against it.

Additional information about circumventing thread limits in LinuxThreads can be found at http://www.volano.com/linuxnotes.html.

There is another issue that greatly hurts MySQL performance, especially on SMP systems. The mutex implementation in LinuxThreads in `glibc` 2.1 is very poor for programs with many threads that hold the mutex only for a short time. This produces a paradoxical result: If you link MySQL against an unmodified LinuxThreads, removing processors from an SMP actually improves MySQL performance in many cases. We have made a patch available for `glibc` 2.1.3 to correct this behavior (http://dev.mysql.com/Downloads/Linux/linuxthreads-2.1-patch).

With `glibc` 2.2.2, MySQL uses the adaptive mutex, which is much better than even the patched one in `glibc` 2.1.3. Be warned, however, that under some conditions, the current mutex code in `glibc` 2.2.2 overspins, which hurts MySQL performance. The likelihood that this condition occurs can be reduced by re-nicing the mysqld process to the highest priority. We have also been able to correct the overspin behavior with a patch, available at http://dev.mysql.com/Downloads/Linux/linuxthreads-2.2.2.patch. It combines the correction of overspin, maximum number of threads, and stack spacing all in one. You need to apply it in the `linuxthreads` directory with `patch -p0 </tmp/linuxthreads-2.2.2.patch`. We hope it is included in some form in future releases of `glibc` 2.2. In any case, if you link against `glibc` 2.2.2, you still need to correct `STACK_SIZE` and `PTHREAD_THREADS_MAX`. We hope that the defaults is corrected to some more acceptable values for high-load MySQL setup in the future, so that the commands needed to produce your own build can be reduced to ./configure; make; make install.

We recommend that you use these patches to build a special static version of `libpthread.a` and use it only for statically linking against MySQL. We know that these patches are safe for MySQL and significantly improve its performance, but we cannot say anything about their effects on other applications. If you link other applications that require LinuxThreads against the patched static version of the library, or build a patched shared version and install it on your system, you do so at your own risk.

If you experience any strange problems during the installation of MySQL, or with some common utilities hanging, it is very likely that they are either library or compiler related. If this is the case, using our binary resolves them.

If you link your own MySQL client programs, you may see the following error at runtime:

    ld.so.1: fatal: libmysqlclient.so.#:
    open failed: No such file or directory

This problem can be avoided by one of the following methods:

- Link clients with the `-Wl,r/full/path/to/libmysqlclient.so` flag rather than with `-Lpath`).

- Copy `libmysqclient.so` to `/usr/lib`.

- Add the pathname of the directory where `libmysqlclient.so` is located to the `LD_RUN_PATH` environment variable before running your client.

If you are using the Fujitsu compiler (`fcc/FCC`), you may have some problems compiling MySQL because the Linux header files are very gcc oriented. The following configure line should work with fcc/FCC:

    CC=fcc CFLAGS="-O -K fast -K lib -K omitfp -Kpreex -D_GNU_SOURCE \
        -DCONST=const -DNO_STRTOLL_PROTO" \
    CXX=FCC CXXFLAGS="-O -K fast -K lib \
        -K omitfp -K preex --no_exceptions --no_rtti -D_GNU_SOURCE \
        -DCONST=const -Dalloca=__builtin_alloca -DNO_STRTOLL_PROTO \
        '-D_EXTERN_INLINE=static __inline'" \
    ./configure \
        --prefix=/usr/local/mysql --enable-assembler \
        --with-mysqld-ldflags=-all-static --disable-shared \
        --with-low-memory

##### 2.4.18.1.4. Linux Post-Installation Notes

mysql.server can be found in the `support-files` directory under the MySQL installation directory or in a MySQL source tree. You can install it as `/etc/init.d/mysql` for automatic MySQL startup and shutdown. See Section 2.4.15.2.2, “Starting and Stopping MySQL Automatically”.

If MySQL cannot open enough files or connections, it may be that you have not configured Linux to handle enough files.

In Linux 2.2 and onward, you can check the number of allocated file handles as follows:

    shell> cat /proc/sys/fs/file-max
    shell> cat /proc/sys/fs/dquot-max
    shell> cat /proc/sys/fs/super-max

If you have more than 16MB of memory, you should add something like the following to your init scripts (for example, `/etc/init.d/boot.local` on SuSE Linux):

    echo 65536 > /proc/sys/fs/file-max
    echo 8192 > /proc/sys/fs/dquot-max
    echo 1024 > /proc/sys/fs/super-max

You can also run the `echo` commands from the command line as `root`, but these settings are lost the next time your computer restarts.

Alternatively, you can set these parameters on startup by using the `sysctl` tool, which is used by many Linux distributions (including SuSE Linux 8.0 and later). Put the following values into a file named `/etc/sysctl.conf`:

    # Increase some values for MySQL
    fs.file-max = 65536
    fs.dquot-max = 8192
    fs.super-max = 1024

You should also add the following to `/etc/my.cnf`:

    [mysqld_safe]
    open-files-limit=8192

This should allow the server a limit of 8,192 for the combined number of connections and open files.

The `STACK_SIZE` constant in LinuxThreads controls the spacing of thread stacks in the address space. It needs to be large enough so that there is plenty of room for each individual thread stack, but small enough to keep the stack of some threads from running into the global mysqld data. Unfortunately, as we have experimentally discovered, the Linux implementation of `mmap()` successfully unmaps a mapped region if you ask it to map out an address currently in use, zeroing out the data on the entire page instead of returning an error. So, the safety of mysqld or any other threaded application depends on the “gentlemanly” behavior of the code that creates threads. The user must take measures to make sure that the number of running threads at any given time is sufficiently low for thread stacks to stay away from the global heap. With mysqld, you should enforce this behavior by setting a reasonable value for the `max_connections` variable.

If you build MySQL yourself, you can patch LinuxThreads for better stack use. See Section 2.4.18.1.3, “Linux Source Distribution Notes”. If you do not want to patch LinuxThreads, you should set `max_connections` to a value no higher than 500. It should be even less if you have a large key buffer, large heap tables, or some other things that make mysqld allocate a lot of memory, or if you are running a 2.2 kernel with a 2GB patch. If you are using our binary or RPM version, you can safely set `max_connections` at 1500, assuming no large key buffer or heap tables with lots of data. The more you reduce `STACK_SIZE` in LinuxThreads the more threads you can safely create. We recommend values between 128KB and 256KB.

If you use a lot of concurrent connections, you may suffer from a “feature” in the 2.2 kernel that attempts to prevent fork bomb attacks by penalizing a process for forking or cloning a child. This causes MySQL not to scale well as you increase the number of concurrent clients. On single-CPU systems, we have seen this manifest as very slow thread creation; it may take a long time to connect to MySQL (as long as one minute), and it may take just as long to shut it down. On multiple-CPU systems, we have observed a gradual drop in query speed as the number of clients increases. In the process of trying to find a solution, we have received a kernel patch from one of our users who claimed it helped for his site. This patch is available at http://dev.mysql.com/Downloads/Patches/linux-fork.patch. We have done rather extensive testing of this patch on both development and production systems. It has significantly improved MySQL performance without causing any problems and we recommend it to our users who still run high-load servers on 2.2 kernels.

This issue has been fixed in the 2.4 kernel, so if you are not satisfied with the current performance of your system, rather than patching your 2.2 kernel, it might be easier to upgrade to 2.4. On SMP systems, upgrading also gives you a nice SMP boost in addition to fixing the fairness bug.

We have tested MySQL on the 2.4 kernel on a two-CPU machine and found MySQL scales much better. There was virtually no slowdown on query throughput all the way up to 1,000 clients, and the MySQL scaling factor (computed as the ratio of maximum throughput to the throughput for one client) was 180%. We have observed similar results on a four-CPU system: Virtually no slowdown as the number of clients was increased up to 1,000, and a 300% scaling factor. Based on these results, for a high-load SMP server using a 2.2 kernel, we definitely recommend upgrading to the 2.4 kernel at this point.

We have discovered that it is essential to run the mysqld process with the highest possible priority on the 2.4 kernel to achieve maximum performance. This can be done by adding a `renice -20 $$` command to mysqld_safe. In our testing on a four-CPU machine, increasing the priority resulted in a 60% throughput increase with 400 clients.

We are currently also trying to collect more information on how well MySQL performs with a 2.4 kernel on four-way and eight-way systems. If you have access such a system and have done some benchmarks, please send an email message to `<benchmarks@mysql.com>` with the results. We will review them for inclusion in the manual.

If you see a dead mysqld server process with ps, this usually means that you have found a bug in MySQL or you have a corrupted table. See Section B.4.2, “What to Do If MySQL Keeps Crashing”.

To get a core dump on Linux if mysqld dies with a `SIGSEGV` signal, you can start mysqld with the `--core-file` option. Note that you also probably need to raise the core file size by adding ulimit -c 1000000 to mysqld_safe or starting mysqld_safe with `--core-file-size=1000000`. See Section 5.4.1, “mysqld_safe — MySQL Server Startup Script”.

##### 2.4.18.1.5. Linux x86 Notes

MySQL requires `libc` 5.4.12 or newer. It is known to work with `libc` 5.4.46. `glibc` 2.0.6 and later should also work. There have been some problems with the `glibc` RPMs from Red Hat, so if you have problems, check whether there are any updates. The `glibc` 2.0.7-19 and 2.0.7-29 RPMs are known to work.

If you are using Red Hat 8.0 or a new `glibc` 2.2.x library, you may see mysqld die in `gethostbyaddr()`. This happens because the new `glibc` library requires a stack size greater than 128KB for this call. To fix the problem, start mysqld with the `--thread-stack=192K` option. (Use `-O thread_stack=192K` before MySQL 4.) This stack size is the default on MySQL 4.0.10 and above, so you should not see the problem.

If you are using gcc 3.0 and above to compile MySQL, you must install the `libstdc++v3` library before compiling MySQL; if you don't do this, you get an error about a missing `__cxa_pure_virtual` symbol during linking.

On some older Linux distributions, configure may produce an error like this:

    Syntax error in sched.h. Change _P to __P in the
    /usr/include/sched.h file.
    See the Installation chapter in the Reference Manual.

Just do what the error message says. Add an extra underscore to the `_P` macro name that has only one underscore, and then try again.

You may get some warnings when compiling. Those shown here can be ignored:

    mysqld.cc -o objs-thread/mysqld.o
    mysqld.cc: In function `void init_signals()':
    mysqld.cc:315: warning: assignment of negative value `-1' to
    `long unsigned int'
    mysqld.cc: In function `void * signal_hand(void *)':
    mysqld.cc:346: warning: assignment of negative value `-1' to
    `long unsigned int'

If mysqld always dumps core when it starts, the problem may be that you have an old `/lib/libc.a`. Try renaming it, and then remove `sql/mysqld` and do a new make install and try again. This problem has been reported on some Slackware installations.

If you get the following error when linking mysqld, it means that your `libg++.a` is not installed correctly:

    /usr/lib/libc.a(putc.o): In function `_IO_putc':
    putc.o(.text+0x0): multiple definition of `_IO_putc'

You can avoid using `libg++.a` by running configure like this:

    shell> CXX=gcc ./configure

##### 2.4.18.1.6. Linux SPARC Notes

In some implementations, `readdir_r()` is broken. The symptom is that the `SHOW DATABASES` statement always returns an empty set. This can be fixed by removing `HAVE_READDIR_R` from `config.h` after configuring and before compiling.

##### 2.4.18.1.7. Linux Alpha Notes

We have tested MySQL 5.0 on Alpha with our benchmarks and test suite, and it appears to work well.

We currently build the MySQL binary packages on SuSE Linux 7.0 for AXP, kernel 2.4.4-SMP, Compaq C compiler (V6.2-505) and Compaq C++ compiler (V6.3-006) on a Compaq DS20 machine with an Alpha EV6 processor.

You can find the preceding compilers at http://www.support.compaq.com/alpha-tools/. By using these compilers rather than gcc, we get about 9-14% better MySQL performance.

For MySQL on Alpha, we use the `-arch generic` flag to our compile options, which ensures that the binary runs on all Alpha processors. We also compile statically to avoid library problems. The configure command looks like this:

    CC=ccc CFLAGS="-fast -arch generic" CXX=cxx \
    CXXFLAGS="-fast -arch generic -noexceptions -nortti" \
    ./configure --prefix=/usr/local/mysql --disable-shared \
        --with-extra-charsets=complex --enable-thread-safe-client \
        --with-mysqld-ldflags=-non_shared --with-client-ldflags=-non_shared

If you want to use egcs, the following configure line worked for us:

    CFLAGS="-O3 -fomit-frame-pointer" CXX=gcc \
    CXXFLAGS="-O3 -fomit-frame-pointer -felide-constructors \
        -fno-exceptions -fno-rtti" \
    ./configure --prefix=/usr/local/mysql --disable-shared

Some known problems when running MySQL on Linux-Alpha:

- Debugging threaded applications like MySQL does not work with `gdb 4.18`. You should use gdb 5.1 instead.

- If you try linking mysqld statically when using gcc, the resulting image dumps core at startup time. In other words, do not use `--with-mysqld-ldflags=-all-static` with gcc.

##### 2.4.18.1.8. Linux PowerPC Notes

MySQL should work on MkLinux with the newest `glibc` package (tested with `glibc` 2.0.7).

##### 2.4.18.1.9. Linux MIPS Notes

To get MySQL to work on Qube2 (Linux Mips), you need the newest `glibc` libraries. `glibc-2.0.7-29C2` is known to work. You must also use the egcs C++ compiler (egcs 1.0.2-9, gcc 2.95.2 or newer).

##### 2.4.18.1.10. Linux IA-64 Notes

To get MySQL to compile on Linux IA-64, we use the following configure command for building with gcc 2.96:

    CC=gcc \
    CFLAGS="-O3 -fno-omit-frame-pointer" \
    CXX=gcc \
    CXXFLAGS="-O3 -fno-omit-frame-pointer -felide-constructors \
        -fno-exceptions -fno-rtti" \
        ./configure --prefix=/usr/local/mysql \
        "--with-comment=Official MySQL binary" \
        --with-extra-charsets=complex

On IA-64, the MySQL client binaries use shared libraries. This means that if you install our binary distribution at a location other than `/usr/local/mysql`, you need to add the path of the directory where you have `libmysqlclient.so` installed either to the `/etc/ld.so.conf` file or to the value of your `LD_LIBRARY_PATH` environment variable.

See Section B.3.1, “Problems Linking to the MySQL Client Library”.

##### 2.4.18.1.11. SELinux Notes

RHEL4 comes with SELinux, which supports tighter access control for processes. If SELinux is enabled (`SELINUX` in `/etc/selinux/config` is set to `enforcing`, `SELINUXTYPE` is set to either `targeted` or `strict`), you might encounter problems installing MySQL AB RPM packages.

Red Hat has an update that solves this. It involves an update of the “security policy” specification to handle the install structure of the RPMs provided by MySQL AB. For further information, see https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=167551 and http://rhn.redhat.com/errata/RHBA-2006-0049.html.

#### 2.4.18.2. Mac OS X Notes

On Mac OS X, tar cannot handle long filenames. If you need to unpack a `.tar.gz` distribution, use gnutar instead.

##### 2.4.18.2.1. Mac OS X 10.x (Darwin)

MySQL should work without major problems on Mac OS X 10.x (Darwin).

Known issues:

- If you have problems with performance under heavy load, try using the `--skip-thread-priority` option to mysqld. This runs all threads with the same priority. On Mac OS X, this gives better performance, at least until Apple fixes its thread scheduler.

- The connection times (`wait_timeout`, `interactive_timeout` and `net_read_timeout`) values are not honored.

  This is probably a signal handling problem in the thread library where the signal doesn't break a pending read and we hope that a future update to the thread libraries will fix this.

Our binary for Mac OS X is compiled on Darwin 6.3 with the following configure line:

    CC=gcc CFLAGS="-O3 -fno-omit-frame-pointer" CXX=gcc \
    CXXFLAGS="-O3 -fno-omit-frame-pointer -felide-constructors \
        -fno-exceptions -fno-rtti" \
        ./configure --prefix=/usr/local/mysql \
        --with-extra-charsets=complex --enable-thread-safe-client \
        --enable-local-infile --disable-shared

See Section 2.4.10, “Installing MySQL on Mac OS X”.

##### 2.4.18.2.2. Mac OS X Server 1.2 (Rhapsody)

For current versions of Mac OS X Server, no operating system changes are necessary before compiling MySQL. Compiling for the Server platform is the same as for the client version of Mac OS X.

For older versions (Mac OS X Server 1.2, a.k.a. Rhapsody), you must first install a pthread package before trying to configure MySQL.

See Section 2.4.10, “Installing MySQL on Mac OS X”.

#### 2.4.18.3. Solaris Notes

For information about installing MySQL on Solaris using PKG distributions, see Section 2.4.11, “Installing MySQL on Solaris”.

On Solaris, you may run into trouble even before you get the MySQL distribution unpacked, as the Solaris tar cannot handle long filenames. This means that you may see errors when you try to unpack MySQL.

If this occurs, you must use GNU tar (gtar) to unpack the distribution. You can find a precompiled copy for Solaris at http://dev.mysql.com/downloads/os-solaris.html.

Sun native threads work only on Solaris 2.5 and higher. For Solaris 2.4 and earlier, MySQL automatically uses MIT-pthreads. See Section 2.4.14.5, “MIT-pthreads Notes”.

If you get the following error from configure, it means that you have something wrong with your compiler installation:

    checking for restartable system calls... configure: error can not
    run test programs while cross compiling

In this case, you should upgrade your compiler to a newer version. You may also be able to solve this problem by inserting the following row into the `config.cache` file:

    ac_cv_sys_restartable_syscalls=${ac_cv_sys_restartable_syscalls='no'}

If you are using Solaris on a SPARC, the recommended compiler is gcc 2.95.2 or 3.2. You can find this at http://gcc.gnu.org/. Note that egcs 1.1.1 and gcc 2.8.1 do not work reliably on SPARC.

The recommended configure line when using gcc 2.95.2 is:

    CC=gcc CFLAGS="-O3" \
    CXX=gcc CXXFLAGS="-O3 -felide-constructors -fno-exceptions -fno-rtti" \
    ./configure --prefix=/usr/local/mysql --with-low-memory \
        --enable-assembler

If you have an UltraSPARC system, you can get 4% better performance by adding `-mcpu=v8 -Wa,-xarch=v8plusa` to the `CFLAGS` and `CXXFLAGS` environment variables.

If you have Sun's Forte 5.0 (or newer) compiler, you can run configure like this:

    CC=cc CFLAGS="-Xa -fast -native -xstrconst -mt" \
    CXX=CC CXXFLAGS="-noex -mt" \
    ./configure --prefix=/usr/local/mysql --enable-assembler

To create a 64-bit binary with Sun's Forte compiler, use the following configuration options:

    CC=cc CFLAGS="-Xa -fast -native -xstrconst -mt -xarch=v9" \
    CXX=CC CXXFLAGS="-noex -mt -xarch=v9" ASFLAGS="-xarch=v9" \
    ./configure --prefix=/usr/local/mysql --enable-assembler

To create a 64-bit Solaris binary using gcc, add `-m64` to `CFLAGS` and `CXXFLAGS` and remove `--enable-assembler` from the configure line.

In the MySQL benchmarks, we obtained a 4% speed increase on UltraSPARC when using Forte 5.0 in 32-bit mode, as compared to using gcc 3.2 with the `-mcpu` flag.

If you create a 64-bit mysqld binary, it is 4% slower than the 32-bit binary, but can handle more threads and memory.

When using Solaris 10 for x86_64, you should mount any filesystems on which you intend to store `InnoDB` files with the `forcedirectio` option. (By default mounting is done without this option.) Failing to do so will cause a significant drop in performance when using the `InnoDB` storage engine on this platform.

If you get a problem with `fdatasync` or `sched_yield`, you can fix this by adding `LIBS=-lrt` to the configure line

For compilers older than WorkShop 5.3, you might have to edit the configure script. Change this line:

    #if !defined(__STDC__) || __STDC__ != 1

To this:

    #if !defined(__STDC__)

If you turn on `__STDC__` with the `-Xc` option, the Sun compiler can't compile with the Solaris `pthread.h` header file. This is a Sun bug (broken compiler or broken include file).

If mysqld issues the following error message when you run it, you have tried to compile MySQL with the Sun compiler without enabling the `-mt` multi-thread option:

    libc internal error: _rmutex_unlock: rmutex not held

Add `-mt` to `CFLAGS` and `CXXFLAGS` and recompile.

If you are using the SFW version of gcc (which comes with Solaris 8), you must add `/opt/sfw/lib` to the environment variable `LD_LIBRARY_PATH` before running configure.

If you are using the gcc available from `sunfreeware.com`, you may have many problems. To avoid this, you should recompile gcc and GNU `binutils` on the machine where you are running them.

If you get the following error when compiling MySQL with gcc, it means that your gcc is not configured for your version of Solaris:

    shell> gcc -O3 -g -O2 -DDBUG_OFF  -o thr_alarm ...
    ./thr_alarm.c: In function `signal_hand':
    ./thr_alarm.c:556: too many arguments to function `sigwait'

The proper thing to do in this case is to get the newest version of gcc and compile it with your current gcc compiler. At least for Solaris 2.5, almost all binary versions of gcc have old, unusable include files that break all programs that use threads, and possibly other programs as well.

Solaris does not provide static versions of all system libraries (`libpthreads` and `libdl`), so you cannot compile MySQL with `--static`. If you try to do so, you get one of the following errors:

    ld: fatal: library -ldl: not found
    undefined reference to `dlopen'
    cannot find -lrt

If you link your own MySQL client programs, you may see the following error at runtime:

    ld.so.1: fatal: libmysqlclient.so.#:
    open failed: No such file or directory

This problem can be avoided by one of the following methods:

- Link clients with the `-Wl,r/full/path/to/libmysqlclient.so` flag rather than with `-Lpath`).

- Copy `libmysqclient.so` to `/usr/lib`.

- Add the pathname of the directory where `libmysqlclient.so` is located to the `LD_RUN_PATH` environment variable before running your client.

If you have problems with configure trying to link with `-lz` when you don't have `zlib` installed, you have two options:

- If you want to be able to use the compressed communication protocol, you need to get and install `zlib` from `ftp.gnu.org`.

- Run configure with the `--with-named-z-libs=no` option when building MySQL.

If you are using gcc and have problems with loading user-defined functions (UDFs) into MySQL, try adding `-lgcc` to the link line for the UDF.

If you would like MySQL to start automatically, you can copy `support-files/mysql.server` to `/etc/init.d` and create a symbolic link to it named `/etc/rc3.d/S99mysql.server`.

If too many processes try to connect very rapidly to mysqld, you should see this error in the MySQL log:

    Error in accept: Protocol error

You might try starting the server with the `--back_log=50` option as a workaround for this. (Use `-O back_log=50` before MySQL 4.)

Solaris doesn't support core files for `setuid()` applications, so you can't get a core file from mysqld if you are using the `--user` option.

##### 2.4.18.3.1. Solaris 2.7/2.8 Notes

Normally, you can use a Solaris 2.6 binary on Solaris 2.7 and 2.8. Most of the Solaris 2.6 issues also apply for Solaris 2.7 and 2.8.

MySQL should be able to detect new versions of Solaris automatically and enable workarounds for the following problems.

Solaris 2.7 / 2.8 has some bugs in the include files. You may see the following error when you use gcc:

    /usr/include/widec.h:42: warning: `getwc' redefined
    /usr/include/wchar.h:326: warning: this is the location of the previous
    definition

If this occurs, you can fix the problem by copying `/usr/include/widec.h` to `.../lib/gcc-lib/os/gcc-version/include` and changing line 41 from this:

    #if     !defined(lint) && !defined(__lint)

To this:

    #if     !defined(lint) && !defined(__lint) && !defined(getwc)

Alternatively, you can edit `/usr/include/widec.h` directly. Either way, after you make the fix, you should remove `config.cache` and run configure again.

If you get the following errors when you run make, it's because configure didn't detect the `curses.h` file (probably because of the error in `/usr/include/widec.h`):

    In file included from mysql.cc:50:
    /usr/include/term.h:1060: syntax error before `,'
    /usr/include/term.h:1081: syntax error before `;'

The solution to this problem is to do one of the following:

- Configure with `CFLAGS=-DHAVE_CURSES_H CXXFLAGS=-DHAVE_CURSES_H ./configure`.

- Edit `/usr/include/widec.h` as indicated in the preceding discussion and re-run configure.

- Remove the `#define HAVE_TERM` line from the `config.h` file and run make again.

If your linker cannot find `-lz` when linking client programs, the problem is probably that your `libz.so` file is installed in `/usr/local/lib`. You can fix this problem by one of the following methods:

- Add `/usr/local/lib` to `LD_LIBRARY_PATH`.

- Add a link to `libz.so` from `/lib`.

- If you are using Solaris 8, you can install the optional `zlib` from your Solaris 8 CD distribution.

- Run configure with the `--with-named-z-libs=no` option when building MySQL.

##### 2.4.18.3.2. Solaris x86 Notes

On Solaris 8 on x86, mysqld dumps core if you remove the debug symbols using `strip`.

If you are using gcc or egcs on Solaris x86 and you experience problems with core dumps under load, you should use the following configure command:

    CC=gcc CFLAGS="-O3 -fomit-frame-pointer -DHAVE_CURSES_H" \
    CXX=gcc \
    CXXFLAGS="-O3 -fomit-frame-pointer -felide-constructors \
        -fno-exceptions -fno-rtti -DHAVE_CURSES_H" \
    ./configure --prefix=/usr/local/mysql

This avoids problems with the `libstdc++` library and with C++ exceptions.

If this doesn't help, you should compile a debug version and run it with a trace file or under gdb. See Section H.1.3, “Debugging mysqld under gdb”.

#### 2.4.18.4. BSD Notes

This section provides information about using MySQL on variants of BSD Unix.

##### 2.4.18.4.1. FreeBSD Notes

FreeBSD 4.x or newer is recommended for running MySQL, because the thread package is much more integrated. To get a secure and stable system, you should use only FreeBSD kernels that are marked `-RELEASE`.

The easiest (and preferred) way to install MySQL is to use the mysql-server and `mysql-client` ports available at http://www.freebsd.org/. Using these ports gives you the following benefits:

- A working MySQL with all optimizations enabled that are known to work on your version of FreeBSD.

- Automatic configuration and build.

- Startup scripts installed in `/usr/local/etc/rc.d`.

- The ability to use `pkg_info -L` to see which files are installed.

- The ability to use `pkg_delete` to remove MySQL if you no longer want it on your machine.

It is recommended you use MIT-pthreads on FreeBSD 2.x, and native threads on FreeBSD 3 and up. It is possible to run with native threads on some late 2.2.x versions, but you may encounter problems shutting down mysqld.

Unfortunately, certain function calls on FreeBSD are not yet fully thread-safe. Most notably, this includes the `gethostbyname()` function, which is used by MySQL to convert hostnames into IP addresses. Under certain circumstances, the mysqld process suddenly causes 100% CPU load and is unresponsive. If you encounter this problem, try to start MySQL using the `--skip-name-resolve` option.

Alternatively, you can link MySQL on FreeBSD 4.x against the LinuxThreads library, which avoids a few of the problems that the native FreeBSD thread implementation has. For a very good comparison of LinuxThreads versus native threads, see Jeremy Zawodny's article FreeBSD or Linux for your MySQL Server? at http://jeremy.zawodny.com/blog/archives/000697.html.

Known problem when using LinuxThreads on FreeBSD is:

- The connection times (`wait_timeout`, `interactive_timeout` and `net_read_timeout`) values are not honored. The symptom is that persistent connections can hang for a very long time without getting closed down and that a 'kill' for a thread will not take affect until the thread does it a new command

  This is probably a signal handling problem in the thread library where the signal doesn't break a pending read. This is supposed to be fixed in FreeBSD 5.0

The MySQL build process requires GNU make (gmake) to work. If GNU make is not available, you must install it first before compiling MySQL.

The recommended way to compile and install MySQL on FreeBSD with gcc (2.95.2 and up) is:

    CC=gcc CFLAGS="-O2 -fno-strength-reduce" \
        CXX=gcc CXXFLAGS="-O2 -fno-rtti -fno-exceptions \
        -felide-constructors -fno-strength-reduce" \
        ./configure --prefix=/usr/local/mysql --enable-assembler
    gmake
    gmake install
    cd /usr/local/mysql
    bin/mysql_install_db --user=mysql
    bin/mysqld_safe &

If you notice that configure uses MIT-pthreads, you should read the MIT-pthreads notes. See Section 2.4.14.5, “MIT-pthreads Notes”.

If you get an error from make install that it can't find `/usr/include/pthreads`, configure didn't detect that you need MIT-pthreads. To fix this problem, remove `config.cache`, and then re-run configure with the `--with-mit-threads` option.

Be sure that your name resolver setup is correct. Otherwise, you may experience resolver delays or failures when connecting to mysqld. Also make sure that the `localhost` entry in the `/etc/hosts` file is correct. The file should start with a line similar to this:

    127.0.0.1       localhost localhost.your.domain

FreeBSD is known to have a very low default file handle limit. See Section B.2.17, “'`File`' Not Found and Similar Errors”. Start the server by using the `--open-files-limit` option for mysqld_safe, or raise the limits for the mysqld user in `/etc/login.conf` and rebuild it with `cap_mkdb /etc/login.conf`. Also be sure that you set the appropriate class for this user in the password file if you are not using the default (use `chpass mysqld-user-name`). See Section 5.4.1, “mysqld_safe — MySQL Server Startup Script”.

FreeBSD limits the size of a process to 512MB, even if you have much more RAM available on the system. So you may get an error such as this:

    Out of memory (Needed 16391 bytes)

In current versions of FreeBSD (at least 4.x and greater), you may increase this limit by adding the following entries to the `/boot/loader.conf` file and rebooting the machine (these are not settings that can be changed at run time with the sysctl command):

    kern.maxdsiz="1073741824" # 1GB
    kern.dfldsiz="1073741824" # 1GB
    kern.maxssiz="134217728" # 128MB

For older versions of FreeBSD, you must recompile your kernel to change the maximum data segment size for a process. In this case, you should look at the `MAXDSIZ` option in the `LINT` config file for more information.

If you get problems with the current date in MySQL, setting the `TZ` variable should help. See Appendix I, Environment Variables.

##### 2.4.18.4.2. NetBSD Notes

To compile on NetBSD, you need GNU make. Otherwise, the build process fails when make tries to run `lint` on C++ files.

##### 2.4.18.4.3. OpenBSD 2.5 Notes

On OpenBSD 2.5, you can compile MySQL with native threads with the following options:

    CFLAGS=-pthread CXXFLAGS=-pthread ./configure --with-mit-threads=no

##### 2.4.18.4.4. BSD/OS Version 2.x Notes

If you get the following error when compiling MySQL, your ulimit value for virtual memory is too low:

    item_func.h: In method
    `Item_func_ge::Item_func_ge(const Item_func_ge &)':
    item_func.h:28: virtual memory exhausted
    make[2]: *** [item_func.o] Error 1

Try using ulimit -v 80000 and run make again. If this doesn't work and you are using bash, try switching to csh or sh; some BSDI users have reported problems with bash and ulimit.

If you are using gcc, you may also use have to use the `--with-low-memory` flag for configure to be able to compile `sql_yacc.cc`.

If you get problems with the current date in MySQL, setting the `TZ` variable should help. See Appendix I, Environment Variables.

##### 2.4.18.4.5. BSD/OS Version 3.x Notes

Upgrade to BSD/OS 3.1. If that is not possible, install BSDIpatch M300-038.

Use the following command when configuring MySQL:

    env CXX=shlicc++ CC=shlicc2 \
    ./configure \
        --prefix=/usr/local/mysql \
        --localstatedir=/var/mysql \
        --without-perl \
        --with-unix-socket-path=/var/mysql/mysql.sock

The following is also known to work:

    env CC=gcc CXX=gcc CXXFLAGS=-O3 \
    ./configure \
        --prefix=/usr/local/mysql \
        --with-unix-socket-path=/var/mysql/mysql.sock

You can change the directory locations if you wish, or just use the defaults by not specifying any locations.

If you have problems with performance under heavy load, try using the `--skip-thread-priority` option to mysqld. This runs all threads with the same priority. On BSDI 3.1, this gives better performance, at least until BSDI fixes its thread scheduler.

If you get the error `virtual memory exhausted` while compiling, you should try using ulimit -v 80000 and running make again. If this doesn't work and you are using bash, try switching to csh or sh; some BSDI users have reported problems with bash and ulimit.

##### 2.4.18.4.6. BSD/OS Version 4.x Notes

BSDI 4.x has some thread-related bugs. If you want to use MySQL on this, you should install all thread-related patches. At least M400-023 should be installed.

On some BSDI 4.x systems, you may get problems with shared libraries. The symptom is that you can't execute any client programs, for example, mysqladmin. In this case, you need to reconfigure not to use shared libraries with the `--disable-shared` option to configure.

Some customers have had problems on BSDI 4.0.1 that the mysqld binary after a while can't open tables. This occurs because some library/system-related bug causes mysqld to change current directory without having asked for that to happen.

The fix is to either upgrade MySQL to at least version 3.23.34 or, after running configure, remove the line `#define HAVE_REALPATH` from `config.h` before running make.

Note that this means that you can't symbolically link a database directories to another database directory or symbolic link a table to another database on BSDI. (Making a symbolic link to another disk is okay).

#### 2.4.18.5. Other Unix Notes

##### 2.4.18.5.1. HP-UX Version 10.20 Notes

This section does not apply to MySQL Enterprise Server users.

There are a couple of small problems when compiling MySQL on HP-UX. We recommend that you use gcc instead of the HP-UX native compiler, because gcc produces better code.

We recommend using gcc 2.95 on HP-UX. Don't use high optimization flags (such as `-O6`) because they may not be safe on HP-UX.

The following configure line should work with gcc 2.95:

    CFLAGS="-I/opt/dce/include -fpic" \
    CXXFLAGS="-I/opt/dce/include -felide-constructors -fno-exceptions \
    -fno-rtti" \
    CXX=gcc \
    ./configure --with-pthread \
        --with-named-thread-libs='-ldce' \
        --prefix=/usr/local/mysql --disable-shared

The following configure line should work with gcc 3.1:

    CFLAGS="-DHPUX -I/opt/dce/include -O3 -fPIC" CXX=gcc \
    CXXFLAGS="-DHPUX -I/opt/dce/include -felide-constructors \
        -fno-exceptions -fno-rtti -O3 -fPIC" \
    ./configure --prefix=/usr/local/mysql \
        --with-extra-charsets=complex --enable-thread-safe-client \
        --enable-local-infile  --with-pthread \
        --with-named-thread-libs=-ldce --with-lib-ccflags=-fPIC
        --disable-shared

##### 2.4.18.5.2. HP-UX Version 11.x Notes

Because of some critical bugs in the standard HP-UX libraries, you should install the following patches before trying to run MySQL on HP-UX 11.0:

    PHKL_22840 Streams cumulative
    PHNE_22397 ARPA cumulative

This solves the problem of getting `EWOULDBLOCK` from `recv()` and `EBADF` from `accept()` in threaded applications.

If you are using gcc 2.95.1 on an unpatched HP-UX 11.x system, you may get the following error:

    In file included from /usr/include/unistd.h:11,
                     from ../include/global.h:125,
                     from mysql_priv.h:15,
                     from item.cc:19:
    /usr/include/sys/unistd.h:184: declaration of C function ...
    /usr/include/sys/pthread.h:440: previous declaration ...
    In file included from item.h:306,
                     from mysql_priv.h:158,
                     from item.cc:19:

The problem is that HP-UX does not define `pthreads_atfork()` consistently. It has conflicting prototypes in `/usr/include/sys/unistd.h`:184 and `/usr/include/sys/pthread.h`:440.

One solution is to copy `/usr/include/sys/unistd.h` into `mysql/include` and edit `unistd.h` and change it to match the definition in `pthread.h`. Look for this line:

    extern int pthread_atfork(void (*prepare)(), void (*parent)(),
                                              void (*child)());

Change it to look like this:

    extern int pthread_atfork(void (*prepare)(void), void (*parent)(void),
                                              void (*child)(void));

After making the change, the following configure line should work:

    CFLAGS="-fomit-frame-pointer -O3 -fpic" CXX=gcc \
    CXXFLAGS="-felide-constructors -fno-exceptions -fno-rtti -O3" \
    ./configure --prefix=/usr/local/mysql --disable-shared

If you are using HP-UX compiler, you can use the following command (which has been tested with cc B.11.11.04):

    CC=cc CXX=aCC CFLAGS=+DD64 CXXFLAGS=+DD64 ./configure \
        --with-extra-character-set=complex

You can ignore any errors of the following type:

    aCC: warning 901: unknown option: `-3': use +help for online
    documentation

If you get the following error from configure, verify that you don't have the path to the K&R compiler before the path to the HP-UX C and C++ compiler:

    checking for cc option to accept ANSI C... no
    configure: error: MySQL requires an ANSI C compiler (and a C++ compiler).
    Try gcc. See the Installation chapter in the Reference Manual.

Another reason for not being able to compile is that you didn't define the `+DD64` flags as just described.

Another possibility for HP-UX 11 is to use the MySQL binaries provided at http://dev.mysql.com/downloads/, which we have built and tested ourselves. We have also received reports that the HP-UX 10.20 binaries supplied by MySQL can be run successfully on HP-UX 11. If you encounter problems, you should be sure to check your HP-UX patch level.

##### 2.4.18.5.3. IBM-AIX notes

Automatic detection of `xlC` is missing from Autoconf, so a number of variables need to be set before running configure. The following example uses the IBM compiler:

    export CC="xlc_r -ma -O3 -qstrict -qoptimize=3 -qmaxmem=8192 "
    export CXX="xlC_r -ma -O3 -qstrict -qoptimize=3 -qmaxmem=8192"
    export CFLAGS="-I /usr/local/include"
    export LDFLAGS="-L /usr/local/lib"
    export CPPFLAGS=$CFLAGS
    export CXXFLAGS=$CFLAGS

    ./configure --prefix=/usr/local \
                    --localstatedir=/var/mysql \
                    --sbindir='/usr/local/bin' \
                    --libexecdir='/usr/local/bin' \
                    --enable-thread-safe-client \
                    --enable-large-files

The preceding options are used to compile the MySQL distribution that can be found at http://www-frec.bull.com/.

If you change the `-O3` to `-O2` in the preceding configure line, you must also remove the `-qstrict` option. This is a limitation in the IBM C compiler.

If you are using gcc or egcs to compile MySQL, you must use the `-fno-exceptions` flag, because the exception handling in gcc/egcs is not thread-safe! (This is tested with egcs 1.1.) There are also some known problems with IBM's assembler that may cause it to generate bad code when used with gcc.

We recommend the following configure line with egcs and gcc 2.95 on AIX:

    CC="gcc -pipe -mcpu=power -Wa,-many" \
    CXX="gcc -pipe -mcpu=power -Wa,-many" \
    CXXFLAGS="-felide-constructors -fno-exceptions -fno-rtti" \
    ./configure --prefix=/usr/local/mysql --with-low-memory

The `-Wa,-many` option is necessary for the compile to be successful. IBM is aware of this problem but is in no hurry to fix it because of the workaround that is available. We don't know if the `-fno-exceptions` is required with gcc 2.95, but because MySQL doesn't use exceptions and the option generates faster code, we recommend that you should always use it with egcs / gcc.

If you get a problem with assembler code, try changing the `-mcpu=`xxx`` option to match your CPU. Typically `power2`, `power`, or `powerpc` may need to be used. Alternatively, you might need to use `604` or `604e`. We are not positive but suspect that `power` would likely be safe most of the time, even on a power2 machine.

If you don't know what your CPU is, execute a `uname -m` command. It produces a string that looks like `000514676700`, with a format of `xxyyyyyymmss` where `xx` and `ss` are always `00`, `yyyyyy` is a unique system ID and `mm` is the ID of the CPU Planar. A chart of these values can be found at http://www16.boulder.ibm.com/pseries/en_US/cmds/aixcmds5/uname.htm.

This gives you a machine type and a machine model you can use to determine what type of CPU you have.

If you have problems with signals (MySQL dies unexpectedly under high load), you may have found an OS bug with threads and signals. In this case, you can tell MySQL not to use signals by configuring as follows:

    CFLAGS=-DDONT_USE_THR_ALARM CXX=gcc \
    CXXFLAGS="-felide-constructors -fno-exceptions -fno-rtti \
    -DDONT_USE_THR_ALARM" \
    ./configure --prefix=/usr/local/mysql --with-debug \
        --with-low-memory

This doesn't affect the performance of MySQL, but has the side effect that you can't kill clients that are “sleeping” on a connection with mysqladmin kill or mysqladmin shutdown. Instead, the client dies when it issues its next command.

On some versions of AIX, linking with `libbind.a` makes `getservbyname()` dump core. This is an AIX bug and should be reported to IBM.

For AIX 4.2.1 and gcc, you have to make the following changes.

After configuring, edit `config.h` and `include/my_config.h` and change the line that says this:

    #define HAVE_SNPRINTF 1

to this:

    #undef HAVE_SNPRINTF

And finally, in `mysqld.cc`, you need to add a prototype for `initgroups()`.

    #ifdef _AIX41
    extern "C" int initgroups(const char *,int);
    #endif

If you need to allocate a lot of memory to the mysqld process, it's not enough to just use ulimit -d unlimited. You may also have to modify mysqld_safe to add a line something like this:

    export LDR_CNTRL='MAXDATA=0x80000000'

You can find more information about using a lot of memory at http://publib16.boulder.ibm.com/pseries/en_US/aixprggd/genprogc/lrg_prg_support.htm.

Users of AIX 4.3 should use gmake instead of the make utility included with AIX.

As of AIX 4.1, the C compiler has been unbundled from AIX as a separate product. We recommend using gcc 3.3.2, which can be obtained here: ftp://ftp.software.ibm.com/aix/freeSoftware/aixtoolbox/RPMS/ppc/gcc/

The steps for compiling MySQL on AIX with gcc 3.3.2 are similar to those for using gcc 2.95 (in particular, the need to edit `config.h` and `my_config.h` after running configure). However, before running configure, you should also patch the `curses.h` file as follows:

    /opt/freeware/lib/gcc-lib/powerpc-ibm-aix5.2.0.0/3.3.2/include/curses.h.ORIG
           Mon Dec 26 02:17:28 2005
    --- /opt/freeware/lib/gcc-lib/powerpc-ibm-aix5.2.0.0/3.3.2/include/curses.h
    Mon Dec 26 02:40:13 2005
    ***************
    *** 2023,2029 ****

      #endif /* _AIX32_CURSES */
    ! #if defined(__USE_FIXED_PROTOTYPES__) || defined(__cplusplus) || defined
    (__STRICT_ANSI__)
      extern int delwin (WINDOW *);
      extern int endwin (void);
      extern int getcurx (WINDOW *);
    --- 2023,2029 ----

      #endif /* _AIX32_CURSES */
    ! #if 0 && (defined(__USE_FIXED_PROTOTYPES__) || defined(__cplusplus)
    || defined
    (__STRICT_ANSI__))
      extern int delwin (WINDOW *);
      extern int endwin (void);
      extern int getcurx (WINDOW *);

##### 2.4.18.5.4. SunOS 4 Notes

This section does not apply to MySQL Enterprise Server users.

On SunOS 4, MIT-pthreads is needed to compile MySQL. This in turn means you need GNU make.

Some SunOS 4 systems have problems with dynamic libraries and libtool. You can use the following configure line to avoid this problem:

    ./configure --disable-shared --with-mysqld-ldflags=-all-static

When compiling `readline`, you may get warnings about duplicate defines. These can be ignored.

When compiling mysqld, there are some `implicit declaration of function` warnings. These can be ignored.

##### 2.4.18.5.5. Alpha-DEC-UNIX Notes (Tru64)

This section does not apply to MySQL Enterprise Server users.

If you are using egcs 1.1.2 on Digital Unix, you should upgrade to gcc 2.95.2, because egcs on DEC has some serious bugs!

When compiling threaded programs under Digital Unix, the documentation recommends using the `-pthread` option for cc and cxx and the `-lmach -lexc` libraries (in addition to `-lpthread`). You should run configure something like this:

    CC="cc -pthread" CXX="cxx -pthread -O" \
    ./configure --with-named-thread-libs="-lpthread -lmach -lexc -lc"

When compiling mysqld, you may see a couple of warnings like this:

    mysqld.cc: In function void handle_connections()':
    mysqld.cc:626: passing long unsigned int *' as argument 3 of
    accept(int,sockadddr *, int *)'

You can safely ignore these warnings. They occur because configure can detect only errors, not warnings.

If you start the server directly from the command line, you may have problems with it dying when you log out. (When you log out, your outstanding processes receive a `SIGHUP` signal.) If so, try starting the server like this:

    nohup mysqld [options] &

`nohup` causes the command following it to ignore any `SIGHUP` signal sent from the terminal. Alternatively, start the server by running mysqld_safe, which invokes mysqld using nohup for you. See Section 5.4.1, “mysqld_safe — MySQL Server Startup Script”.

If you get a problem when compiling `mysys/get_opt.c`, just remove the `#define _NO_PROTO` line from the start of that file.

If you are using Compaq's CC compiler, the following configure line should work:

    CC="cc -pthread"
    CFLAGS="-O4 -ansi_alias -ansi_args -fast -inline speed \
            -speculate all -arch host"
    CXX="cxx -pthread"
    CXXFLAGS="-O4 -ansi_alias -ansi_args -fast -inline speed \
              -speculate all -arch host -noexceptions -nortti"
    export CC CFLAGS CXX CXXFLAGS
    ./configure \
        --prefix=/usr/local/mysql \
        --with-low-memory \
        --enable-large-files \
        --enable-shared=yes \
        --with-named-thread-libs="-lpthread -lmach -lexc -lc"
    gnumake

If you get a problem with libtool when compiling with shared libraries as just shown, when linking mysql, you should be able to get around this by issuing these commands:

    cd mysql
    /bin/sh ../libtool --mode=link cxx -pthread  -O3 -DDBUG_OFF \
        -O4 -ansi_alias -ansi_args -fast -inline speed \
        -speculate all \ -arch host  -DUNDEF_HAVE_GETHOSTBYNAME_R \
        -o mysql  mysql.o readline.o sql_string.o completion_hash.o \
        ../readline/libreadline.a -lcurses \
        ../libmysql/.libs/libmysqlclient.so  -lm
    cd ..
    gnumake
    gnumake install
    scripts/mysql_install_db

##### 2.4.18.5.6. Alpha-DEC-OSF/1 Notes

This section does not apply to MySQL Enterprise Server users.

If you have problems compiling and have DEC CC and gcc installed, try running configure like this:

    CC=cc CFLAGS=-O CXX=gcc CXXFLAGS=-O3 \
    ./configure --prefix=/usr/local/mysql

If you get problems with the `c_asm.h` file, you can create and use a 'dummy' `c_asm.h` file with:

    touch include/c_asm.h
    CC=gcc CFLAGS=-I./include \
    CXX=gcc CXXFLAGS=-O3 \
    ./configure --prefix=/usr/local/mysql

Note that the following problems with the ld program can be fixed by downloading the latest DEC (Compaq) patch kit from: http://ftp.support.compaq.com/public/unix/.

On OSF/1 V4.0D and compiler "DEC C V5.6-071 on Digital Unix V4.0 (Rev. 878)," the compiler had some strange behavior (undefined `asm` symbols). `/bin/ld` also appears to be broken (problems with `_exit undefined` errors occurring while linking mysqld). On this system, we have managed to compile MySQL with the following configure line, after replacing `/bin/ld` with the version from OSF 4.0C:

    CC=gcc CXX=gcc CXXFLAGS=-O3 ./configure --prefix=/usr/local/mysql

With the Digital compiler "C++ V6.1-029," the following should work:

    CC=cc -pthread
    CFLAGS=-O4 -ansi_alias -ansi_args -fast -inline speed \
           -speculate all -arch host
    CXX=cxx -pthread
    CXXFLAGS=-O4 -ansi_alias -ansi_args -fast -inline speed \
             -speculate all -arch host -noexceptions -nortti
    export CC CFLAGS CXX CXXFLAGS
    ./configure --prefix=/usr/mysql/mysql \
                --with-mysqld-ldflags=-all-static --disable-shared \
                --with-named-thread-libs="-lmach -lexc -lc"

In some versions of OSF/1, the `alloca()` function is broken. Fix this by removing the line in `config.h` that defines `'HAVE_ALLOCA'`.

The `alloca()` function also may have an incorrect prototype in `/usr/include/alloca.h`. This warning resulting from this can be ignored.

configure uses the following thread libraries automatically: `--with-named-thread-libs="-lpthread -lmach -lexc -lc"`.

When using gcc, you can also try running configure like this:

    CFLAGS=-D_PTHREAD_USE_D4 CXX=gcc CXXFLAGS=-O3 ./configure ...

If you have problems with signals (MySQL dies unexpectedly under high load), you may have found an OS bug with threads and signals. In this case, you can tell MySQL not to use signals by configuring with:

    CFLAGS=-DDONT_USE_THR_ALARM \
    CXXFLAGS=-DDONT_USE_THR_ALARM \
    ./configure ...

This does not affect the performance of MySQL, but has the side effect that you can't kill clients that are “sleeping” on a connection with mysqladmin kill or mysqladmin shutdown. Instead, the client dies when it issues its next command.

With gcc 2.95.2, you may encounter the following compile error:

    sql_acl.cc:1456: Internal compiler error in `scan_region',
    at except.c:2566
    Please submit a full bug report.

To fix this, you should change to the `sql` directory and do a cut-and-paste of the last gcc line, but change `-O3` to `-O0` (or add `-O0` immediately after gcc if you don't have any `-O` option on your compile line). After this is done, you can just change back to the top-level directory and run make again.

##### 2.4.18.5.7. SGI Irix Notes

This section does not apply to MySQL Enterprise Server users.

As of MySQL 5.0, we don't provide binaries for Irix any more.

If you are using Irix 6.5.3 or newer, mysqld is able to create threads only if you run it as a user that has `CAP_SCHED_MGT` privileges (such as `root`) or give the mysqld server this privilege with the following shell command:

    chcap "CAP_SCHED_MGT+epi" /opt/mysql/libexec/mysqld

You may have to undefine some symbols in `config.h` after running configure and before compiling.

In some Irix implementations, the `alloca()` function is broken. If the mysqld server dies on some `SELECT` statements, remove the lines from `config.h` that define `HAVE_ALLOC` and `HAVE_ALLOCA_H`. If mysqladmin create doesn't work, remove the line from `config.h` that defines `HAVE_READDIR_R`. You may have to remove the `HAVE_TERM_H` line as well.

SGI recommends that you install all the patches on this page as a set: http://support.sgi.com/surfzone/patches/patchset/6.2_indigo.rps.html

At the very minimum, you should install the latest kernel rollup, the latest `rld` rollup, and the latest `libc` rollup.

You definitely need all the POSIX patches on this page, for pthreads support:

http://support.sgi.com/surfzone/patches/patchset/6.2_posix.rps.html

If you get the something like the following error when compiling `mysql.cc`:

    "/usr/include/curses.h", line 82: error(1084):
    invalid combination of type

Type the following in the top-level directory of your MySQL source tree:

    extra/replace bool curses_bool < /usr/include/curses.h > include/curses.h
    make

There have also been reports of scheduling problems. If only one thread is running, performance is slow. Avoid this by starting another client. This may lead to a two-to-tenfold increase in execution speed thereafter for the other thread. This is a poorly understood problem with Irix threads; you may have to improvise to find solutions until this can be fixed.

If you are compiling with gcc, you can use the following configure command:

    CC=gcc CXX=gcc CXXFLAGS=-O3 \
    ./configure --prefix=/usr/local/mysql --enable-thread-safe-client \
        --with-named-thread-libs=-lpthread

On Irix 6.5.11 with native Irix C and C++ compilers ver. 7.3.1.2, the following is reported to work

    CC=cc CXX=CC CFLAGS='-O3 -n32 -TARG:platform=IP22 -I/usr/local/include \
    -L/usr/local/lib' CXXFLAGS='-O3 -n32 -TARG:platform=IP22 \
    -I/usr/local/include -L/usr/local/lib' \
    ./configure --prefix=/usr/local/mysql --with-innodb --with-berkeley-db \
        --with-libwrap=/usr/local \
        --with-named-curses-libs=/usr/local/lib/libncurses.a

##### 2.4.18.5.8. SCO UNIX and OpenServer 5.0.x Notes

The current port is tested only on `sco3.2v5.0.5`, `sco3.2v5.0.6`, and `sco3.2v5.0.7` systems. There has also been progress on a port to `sco3.2v4.2`. Open Server 5.0.8 (Legend) has native threads and allows files greater than 2GB. The current maximum file size is 2GB.

We have been able to compile MySQL with the following configure command on OpenServer with gcc 2.95.3.

    CC=gcc CFLAGS="-D_FILE_OFFSET_BITS=64 -O3" \
    CXX=gcc CXXFLAGS="-D_FILE_OFFSET_BITS=64 -O3" \
    ./configure --prefix=/usr/local/mysql \
        --enable-thread-safe-client --with-innodb \
        --with-openssl --with-vio --with-extra-charsets=complex

gcc is available at ftp://ftp.sco.com/pub/openserver5/opensrc/gnutools-5.0.7Kj.

This development system requires the OpenServer Execution Environment Supplement oss646B on OpenServer 5.0.6 and oss656B and The OpenSource libraries found in gwxlibs. All OpenSource tools are in the `opensrc` directory. They are available at ftp://ftp.sco.com/pub/openserver5/opensrc/.

We recommend using the latest production release of MySQL.

SCO provides operating system patches at ftp://ftp.sco.com/pub/openserver5 for OpenServer 5.0.[0-6] and ftp://ftp.sco.com/pub/openserverv5/507 for OpenServer 5.0.7.

SCO provides information about security fixes at ftp://ftp.sco.com/pub/security/OpenServer for OpenServer 5.0.x.

The maximum file size on an OpenSever 5.0.x system is 2GB.

The total memory which can be allocated for streams buffers, clists, and lock records cannot exceed 60MB on OpenServer 5.0.x.

Streams buffers are allocated in units of 4096 byte pages, clists are 70 bytes each, and lock records are 64 bytes each, so:

    (NSTRPAGES × 4096) + (NCLIST × 70) + (MAX_FLCKREC × 64) <= 62914560

Follow this procedure to configure the Database Services option. If you are unsure whether an application requires this, see the documentation provided with the application.

1. Log in as `root`.

2. Enable the SUDS driver by editing the `/etc/conf/sdevice.d/suds` file. Change the `N` in the second field to a `Y`.

3. Use mkdev aio or the Hardware/Kernel Manager to enable support for asynchronous I/O and relink the kernel. To allow users to lock down memory for use with this type of I/O, update the aiomemlock(F) file. This file should be updated to include the names of users that can use AIO and the maximum amounts of memory they can lock down.

4. Many applications use setuid binaries so that you need to specify only a single user. See the documentation provided with the application to determine whether this is the case for your application.

After you complete this process, reboot the system to create a new kernel incorporating these changes.

By default, the entries in `/etc/conf/cf.d/mtune` are set as follows:

    Value           Default         Min             Max
    -----           -------         ---             ---
    NBUF            0               24              450000
    NHBUF           0               32              524288
    NMPBUF          0               12              512
    MAX_INODE       0               100             64000
    MAX_FILE        0               100             64000
    CTBUFSIZE       128             0               256
    MAX_PROC        0               50              16000
    MAX_REGION      0               500             160000
    NCLIST          170             120             16640
    MAXUP           100             15              16000
    NOFILES         110             60              11000
    NHINODE         128             64              8192
    NAUTOUP         10              0               60
    NGROUPS         8               0               128
    BDFLUSHR        30              1               300
    MAX_FLCKREC     0               50              16000
    PUTBUFSZ        8000            2000            20000
    MAXSLICE        100             25              100
    ULIMIT          4194303         2048            4194303
    * Streams Parameters
    NSTREAM         64              1               32768
    NSTRPUSH        9               9               9
    NMUXLINK        192             1               4096
    STRMSGSZ        16384           4096            524288
    STRCTLSZ        1024            1024            1024
    STRMAXBLK       524288          4096            524288
    NSTRPAGES       500             0               8000
    STRSPLITFRAC    80              50              100
    NLOG            3               3               3
    NUMSP           64              1               256
    NUMTIM          16              1               8192
    NUMTRW          16              1               8192
    * Semaphore Parameters
    SEMMAP          10              10              8192
    SEMMNI          10              10              8192
    SEMMNS          60              60              8192
    SEMMNU          30              10              8192
    SEMMSL          25              25              150
    SEMOPM          10              10              1024
    SEMUME          10              10              25
    SEMVMX          32767           32767           32767
    SEMAEM          16384           16384           16384
    * Shared Memory Parameters
    SHMMAX          524288          131072          2147483647
    SHMMIN          1               1               1
    SHMMNI          100             100             2000
    FILE            0               100             64000
    NMOUNT          0               4               256
    NPROC           0               50              16000
    NREGION         0               500             160000

We recommend setting these values as follows:

- `NOFILES` should be 4096 or 2048.

- `MAXUP` should be 2048.

To make changes to the kernel, use the idtune `name parameter` command. idtune modifies the `/etc/conf/cf.d/stune` file for you. For example, to change `SEMMS` to `200`, execute this command as `root`:

    # /etc/conf/bin/idtune SEMMNS 200

Then rebuild and reboot the kernel by issuing this command:

    # /etc/conf/bin/idbuild -B && init 6

We recommend tuning the system, but the proper parameter values to use depend on the number of users accessing the application or database and size the of the database (that is, the used buffer pool). The following kernel parameters can be set with idtune:

- `SHMMAX` (recommended setting: 128MB) and `SHMSEG` (recommended setting: 15). These parameters have an influence on the MySQL database engine to create user buffer pools.

- `NOFILES` and `MAXUP` should be set to at least 2048.

- `MAXPROC` should be set to at least 3000/4000 (depends on number of users) or more.

- We also recommend using the following formulas to calculate values for `SEMMSL`, `SEMMNS`, and `SEMMNU`:

      SEMMSL = 13

  13 is what has been found to be the best for both Progress and MySQL.

      SEMMNS = SEMMSL × number of db servers to be run on the system

  Set `SEMMNS` to the value of `SEMMSL` multiplied by the number of database servers (maximum) that you are running on the system at one time.

      SEMMNU = SEMMNS

  Set the value of `SEMMNU` to equal the value of `SEMMNS`. You could probably set this to 75% of `SEMMNS`, but this is a conservative estimate.

You need to at least install the SCO OpenServer Linker and Application Development Libraries or the OpenServer Development System to use gcc. You cannot use the GCC Dev system without installing one of these.

You should get the FSU Pthreads package and install it first. This can be found at http://moss.csc.ncsu.edu/~mueller/ftp/pub/PART/pthreads.tar.gz. You can also get a precompiled package from ftp://ftp.zenez.com/pub/zenez/prgms/FSU-threads-3.14.tar.gz.

FSU Pthreads can be compiled with SCO Unix 4.2 with tcpip, or using OpenServer 3.0 or Open Desktop 3.0 (OS 3.0 ODT 3.0) with the SCO Development System installed using a good port of GCC 2.5.x. For ODT or OS 3.0, you need a good port of GCC 2.5.x. There are a lot of problems without a good port. The port for this product requires the SCO Unix Development system. Without it, you are missing the libraries and the linker that is needed. You also need `SCO-3.2v4.2-includes.tar.gz`. This file contains the changes to the SCO Development include files that are needed to get MySQL to build. You need to replace the existing system include files with these modified header files. They can be obtained from ftp://ftp.zenez.com/pub/zenez/prgms/SCO-3.2v4.2-includes.tar.gz.

To build FSU Pthreads on your system, all you should need to do is run GNU make. The `Makefile` in FSU-threads-3.14.tar.gz is set up to make FSU-threads.

You can run ./configure in the `threads/src` directory and select the SCO OpenServer option. This command copies `Makefile.SCO5` to `Makefile`. Then run make.

To install in the default `/usr/include` directory, log in as `root`, and then `cd` to the `thread/src` directory and run make install.

Remember that you must use GNU make to build MySQL.

Note: If you don't start mysqld_safe as `root`, you should get only the default 110 open files per process. mysqld writes a note about this in the log file.

With SCO 3.2V4.2, you should use FSU Pthreads version 3.14 or newer. The following configure command should work:

    CFLAGS="-D_XOPEN_XPG4" CXX=gcc CXXFLAGS="-D_XOPEN_XPG4" \
    ./configure \
        --prefix=/usr/local/mysql \
        --with-named-thread-libs="-lgthreads -lsocket -lgen -lgthreads" \
        --with-named-curses-libs="-lcurses"

You may have problems with some include files. In this case, you can find new SCO-specific include files at ftp://ftp.zenez.com/pub/zenez/prgms/SCO-3.2v4.2-includes.tar.gz.

You should unpack this file in the `include` directory of your MySQL source tree.

SCO development notes:

- MySQL should automatically detect FSU Pthreads and link mysqld with `-lgthreads -lsocket -lgthreads`.

- The SCO development libraries are re-entrant in FSU Pthreads. SCO claims that its library functions are re-entrant, so they must be re-entrant with FSU Pthreads. FSU Pthreads on OpenServer tries to use the SCO scheme to make re-entrant libraries.

- FSU Pthreads (at least the version at ftp://ftp.zenez.com) comes linked with GNU `malloc`. If you encounter problems with memory usage, make sure that `gmalloc.o` is included in `libgthreads.a` and `libgthreads.so`.

- In FSU Pthreads, the following system calls are pthreads-aware: `read()`, `write()`, `getmsg()`, `connect()`, `accept(),` `select()`, and `wait()`.

- The CSSA-2001-SCO.35.2 (the patch is listed in custom as erg711905-dscr_remap security patch (version 2.0.0)) breaks FSU threads and makes mysqld unstable. You have to remove this one if you want to run mysqld on an OpenServer 5.0.6 machine.

- If you use SCO OpenServer 5, you may need to recompile FSU pthreads with `-DDRAFT7` in `CFLAGS`. Otherwise, `InnoDB` may hang at a mysqld startup.

- SCO provides operating system patches at ftp://ftp.sco.com/pub/openserver5 for OpenServer 5.0.x.

- SCO provides security fixes and `libsocket.so.2` at ftp://ftp.sco.com/pub/security/OpenServer and ftp://ftp.sco.com/pub/security/sse for OpenServer 5.0.x.

- Pre-OSR506 security fixes. Also, the `telnetd` fix at ftp://stage.caldera.com/pub/security/openserver/ or ftp://stage.caldera.com/pub/security/openserver/CSSA-2001-SCO.10/ as both `libsocket.so.2` and `libresolv.so.1` with instructions for installing on pre-OSR506 systems.

  It's probably a good idea to install these patches before trying to compile/use MySQL.

Beginning with Legend/OpenServer 6.0.0, there are native threads and no 2GB file size limit.

##### 2.4.18.5.9. SCO OpenServer 6.0.x Notes

OpenServer 6 includes these key improvements:

- Larger file support up to 1 TB

- Multiprocessor support increased from 4 to 32 processors

- Increased memory support up to 64GB

- Extending the power of UnixWare into OpenServer 6

- Dramatic performance improvement

OpenServer 6.0.0 commands are organized as follows:

- `/bin` is for commands that behave exactly the same as on OpenServer 5.0.x.

- `/u95/bin` is for commands that have better standards conformance, for example Large File System (LFS) support.

- `/udk/bin` is for commands that behave the same as on UnixWare 7.1.4. The default is for the LFS support.

The following is a guide to setting `PATH` on OpenServer 6. If the user wants the traditional OpenServer 5.0.x then `PATH` should be `/bin` first. If the user wants LFS support, the path should be `/u95/bin:/bin`. If the user wants UnixWare 7 support first, the path would be `/udk/bin:/u95/bin:/bin:`.

We recommend using the latest production release of MySQL. Should you choose to use an older release of MySQL on OpenServer 6.0.x, you must use a version of MySQL at least as recent as 3.22.13 to get fixes for some portability and OS problems.

MySQL distribution files with names of the following form are tar archives of media are tar archives of media images suitable for installation with the SCO Software Manager (`/etc/custom`) on SCO OpenServer 6:

    mysql-PRODUCT-5.0.34-sco-osr6-i686.VOLS.tar

A distribution where `PRODUCT` is `pro-cert` is the Commercially licensed MySQL Pro Certified server. A distribution where `PRODUCT` is `pro-gpl-cert` is the MySQL Pro Certified server licensed under the terms of the General Public License (GPL).

Select whichever distribution you wish to install and, after download, extract the tar archive into an empty directory. For example:

    shell> mkdir /tmp/mysql-pro
    shell> cd /tmp/mysql-pro
    shell> tar xf /tmp/mysql-pro-cert-5.0.34-sco-osr6-i686.VOLS.tar

Prior to installation, back up your data in accordance with the procedures outlined in Section 2.4.16, “Upgrading MySQL”.

Remove any previously installed pkgadd version of MySQL:

    shell> pkginfo mysql 2>&1 > /dev/null && pkgrm mysql

Install MySQL Pro from media images using the SCO Software Manager:

    shell> /etc/custom -p SCO:MySQL -i -z /tmp/mysql-pro

Alternatively, the SCO Software Manager can be displayed graphically by clicking on the `Software Manager` icon on the desktop, selecting `Software -> Install New`, selecting the host, selecting `Media Images` for the Media Device, and entering `/tmp/mysql-pro` as the Image Directory.

After installation, run mkdev mysql as the `root` user to configure your newly installed MySQL Pro Certified server.

Note: The installation procedure for VOLS packages does not create the `mysql` user and group that the package uses by default. You should either create the `mysql` user and group, or else select a different user and group using an option in mkdev mysql.

If you wish to configure your MySQL Pro server to interface with the Apache Web server via PHP, download and install the PHP update from SCO at ftp://ftp.sco.com/pub/updates/OpenServer/SCOSA-2006.17/.

We have been able to compile MySQL with the following configure command on OpenServer 6.0.x:

    CC=cc CFLAGS="-D_FILE_OFFSET_BITS=64 -O3" \
    CXX=CC CXXFLAGS="-D_FILE_OFFSET_BITS=64 -O3" \
    ./configure --prefix=/usr/local/mysql \
        --enable-thread-safe-client --with-berkeley-db \
        --with-extra-charsets=complex \
        --build=i686-unknown-sysv5SCO_SV6.0.0

If you use gcc, you must use gcc 2.95.3 or newer.

    CC=gcc CXX=g++ ... ./configure ...

The version of Berkeley DB that comes with either UnixWare 7.1.4 or OpenServer 6.0.0 is not used when building MySQL. MySQL instead uses its own version of Berkeley DB. The configure command needs to build both a static and a dynamic library in ``src_directory`/bdb/build_unix/`, but it does not with MySQL's own `BDB` version. The workaround is as follows.

1. Configure as normal for MySQL.

2. `cd bdb/build_unix/`

3. `cp -p Makefile Makefile.sav`

4. Use same options and run ../dist/configure.

5. Run gmake.

6. `cp -p Makefile.sav Makefile`

7. Change location to the top source directory and run gmake.

This allows both the shared and dynamic libraries to be made and work.

SCO provides OpenServer 6 operating system patches at ftp://ftp.sco.com/pub/openserver6.

SCO provides information about security fixes at ftp://ftp.sco.com/pub/security/OpenServer.

By default, the maximum file size on a OpenServer 6.0.0 system is 1TB. Some operating system utilities have a limitation of 2GB. The maximum possible file size on UnixWare 7 is 1TB with VXFS or HTFS.

OpenServer 6 can be configured for large file support (file sizes greater than 2GB) by tuning the UNIX kernel.

By default, the entries in `/etc/conf/cf.d/mtune` are set as follows:

    Value           Default         Min             Max
    -----           -------         ---             ---
    SVMMLIM         0x9000000       0x1000000       0x7FFFFFFF
    HVMMLIM         0x9000000       0x1000000       0x7FFFFFFF

To make changes to the kernel, use the idtune `name parameter` command. idtune modifies the `/etc/conf/cf.d/stune` file for you. We recommend setting the kernel values by executing the following commands as `root`:

    # /etc/conf/bin/idtune SDATLIM 0x7FFFFFFF
    # /etc/conf/bin/idtune HDATLIM 0x7FFFFFFF
    # /etc/conf/bin/idtune SVMMLIM 0x7FFFFFFF
    # /etc/conf/bin/idtune HVMMLIM 0x7FFFFFFF
    # /etc/conf/bin/idtune SFNOLIM 2048
    # /etc/conf/bin/idtune HFNOLIM 2048

Then rebuild and reboot the kernel by issuing this command:

    # /etc/conf/bin/idbuild -B && init 6

We recommend tuning the system, but the proper parameter values to use depend on the number of users accessing the application or database and size the of the database (that is, the used buffer pool). The following kernel parameters can be set with idtune:

- `SHMMAX` (recommended setting: 128MB) and `SHMSEG` (recommended setting: 15). These parameters have an influence on the MySQL database engine to create user buffer pools.

- `SFNOLIM` and `HFNOLIM` should be at maximum 2048.

- `NPROC` should be set to at least 3000/4000 (depends on number of users).

- We also recommend using the following formulas to calculate values for `SEMMSL`, `SEMMNS`, and `SEMMNU`:

      SEMMSL = 13

  13 is what has been found to be the best for both Progress and MySQL.

      SEMMNS = SEMMSL × number of db servers to be run on the system

  Set `SEMMNS` to the value of `SEMMSL` multiplied by the number of database servers (maximum) that you are running on the system at one time.

      SEMMNU = SEMMNS

  Set the value of `SEMMNU` to equal the value of `SEMMNS`. You could probably set this to 75% of `SEMMNS`, but this is a conservative estimate.

##### 2.4.18.5.10. SCO UnixWare 7.1.x and OpenUNIX 8.0.0 Notes

We recommend using the latest production release of MySQL. Should you choose to use an older release of MySQL on UnixWare 7.1.x, you must use a version of MySQL at least as recent as 3.22.13 to get fixes for some portability and OS problems.

We have been able to compile MySQL with the following configure command on UnixWare 7.1.x:

    CC="cc" CFLAGS="-I/usr/local/include" \
    CXX="CC" CXXFLAGS="-I/usr/local/include" \
    ./configure --prefix=/usr/local/mysql \
        --enable-thread-safe-client --with-berkeley-db=./bdb \
        --with-innodb --with-openssl --with-extra-charsets=complex

If you want to use gcc, you must use gcc 2.95.3 or newer.

    CC=gcc CXX=g++ ... ./configure ...

The version of Berkeley DB that comes with either UnixWare 7.1.4 or OpenServer 6.0.0 is not used when building MySQL. MySQL instead uses its own version of Berkeley DB. The configure command needs to build both a static and a dynamic library in ``src_directory`/bdb/build_unix/`, but it does not with MySQL's own `BDB` version. The workaround is as follows.

1. Configure as normal for MySQL.

2. `cd bdb/build_unix/`

3. `cp -p Makefile Makefile.sav`

4. Use same options and run ../dist/configure.

5. Run gmake.

6. `cp -p Makefile.sav Makefile`

7. Change to top source directory and run gmake.

This allows both the shared and dynamic libraries to be made and work.

SCO provides operating system patches at ftp://ftp.sco.com/pub/unixware7 for UnixWare 7.1.1, ftp://ftp.sco.com/pub/unixware7/713/ for UnixWare 7.1.3, ftp://ftp.sco.com/pub/unixware7/714/ for UnixWare 7.1.4, and ftp://ftp.sco.com/pub/openunix8 for OpenUNIX 8.0.0.

SCO provides information about security fixes at ftp://ftp.sco.com/pub/security/OpenUNIX for OpenUNIX and ftp://ftp.sco.com/pub/security/UnixWare for UnixWare.

The UnixWare 7 file size limit is 1 TB with VXFS. Some OS utilities have a limitation of 2GB.

On UnixWare 7.1.4 you do not need to do anything to get large file support, but to enable large file support on prior versions of UnixWare 7.1.x, run fsadm.

    # fsadm -Fvxfs -o largefiles /
    # fsadm /         * Note
    # ulimit unlimited
    # /etc/conf/bin/idtune SFSZLIM 0x7FFFFFFF     ** Note
    # /etc/conf/bin/idtune HFSZLIM 0x7FFFFFFF     ** Note
    # /etc/conf/bin/idbuild -B

    * This should report "largefiles".
    ** 0x7FFFFFFF represents infinity for these values.

Reboot the system using `shutdown`.

By default, the entries in `/etc/conf/cf.d/mtune` are set as follows:

    Value           Default         Min             Max
    -----           -------         ---             ---
    SVMMLIM         0x9000000       0x1000000       0x7FFFFFFF
    HVMMLIM         0x9000000       0x1000000       0x7FFFFFFF

To make changes to the kernel, use the idtune `name parameter` command. idtune modifies the `/etc/conf/cf.d/stune` file for you. We recommend setting the kernel values by executing the following commands as `root`:

    # /etc/conf/bin/idtune SDATLIM 0x7FFFFFFF
    # /etc/conf/bin/idtune HDATLIM 0x7FFFFFFF
    # /etc/conf/bin/idtune SVMMLIM 0x7FFFFFFF
    # /etc/conf/bin/idtune HVMMLIM 0x7FFFFFFF
    # /etc/conf/bin/idtune SFNOLIM 2048
    # /etc/conf/bin/idtune HFNOLIM 2048

Then rebuild and reboot the kernel by issuing this command:

    # /etc/conf/bin/idbuild -B && init 6

We recommend tuning the system, but the proper parameter values to use depend on the number of users accessing the application or database and size the of the database (that is, the used buffer pool). The following kernel parameters can be set with idtune:

- `SHMMAX` (recommended setting: 128MB) and `SHMSEG` (recommended setting: 15). These parameters have an influence on the MySQL database engine to create user buffer pools.

- `SFNOLIM` and `HFNOLIM` should be at maximum 2048.

- `NPROC` should be set to at least 3000/4000 (depends on number of users).

- We also recommend using the following formulas to calculate values for `SEMMSL`, `SEMMNS`, and `SEMMNU`:

      SEMMSL = 13

  13 is what has been found to be the best for both Progress and MySQL.

      SEMMNS = SEMMSL × number of db servers to be run on the system

  Set `SEMMNS` to the value of `SEMMSL` multiplied by the number of database servers (maximum) that you are running on the system at one time.

      SEMMNU = SEMMNS

  Set the value of `SEMMNU` to equal the value of `SEMMNS`. You could probably set this to 75% of `SEMMNS`, but this is a conservative estimate.

#### 2.4.18.6. OS/2 Notes

This section does not apply to MySQL Enterprise Server users.

MySQL uses quite a few open files. Because of this, you should add something like the following to your `CONFIG.SYS` file:

    SET EMXOPT=-c -n -h1024

If you do not do this, you may encounter the following error:

    File 'xxxx' not found (Errcode: 24)

When using MySQL with OS/2 Warp 3, FixPack 29 or above is required. With OS/2 Warp 4, FixPack 4 or above is required. This is a requirement of the Pthreads library. MySQL must be installed on a partition with a type that supports long filenames, such as HPFS, FAT32, and so on.

The INSTALL.CMD script must be run from OS/2's own CMD.EXE and may not work with replacement shells such as 4OS2.EXE.

The `scripts/mysql-install-db` script has been renamed. It is called `install.cmd` and is a REXX script, which sets up the default MySQL security settings and creates the WorkPlace Shell icons for MySQL.

Dynamic module support is compiled in but not fully tested. Dynamic modules should be compiled using the Pthreads runtime library.

    gcc -Zdll -Zmt -Zcrtdll=pthrdrtl -I../include -I../regex -I.. \
        -o example udf_example.c -L../lib -lmysqlclient udf_example.def
    mv example.dll example.udf

Note: Due to limitations in OS/2, UDF module name stems must not exceed eight characters. Modules are stored in the `/mysql2/udf` directory; the `safe-mysqld.cmd` script puts this directory in the `BEGINLIBPATH` environment variable. When using UDF modules, specified extensions are ignored---it is assumed to be `.udf`. For example, in Unix, the shared module might be named `example.so` and you would load a function from it like this:

    mysql> CREATE FUNCTION metaphon RETURNS STRING SONAME 'example.so';

In OS/2, the module would be named `example.udf`, but you would not specify the module extension:

    mysql> CREATE FUNCTION metaphon RETURNS STRING SONAME 'example';

### 2.4.19. Perl Installation Notes

Perl support for MySQL is provided by means of the `DBI`/`DBD` client interface. The interface requires Perl 5.6.1 or later. It does not work if you have an older version of Perl.

If you want to use transactions with Perl DBI, you need to have `DBD::mysql` version 1.2216 or newer. `DBD::mysql` 2.9003 or newer is recommended.

If you are using the MySQL 4.1 or newer client library, you must use `DBD::mysql` 2.9003 or newer.

Perl support is not included with MySQL distributions. You can obtain the necessary modules from http://search.cpan.org for Unix, or by using the ActiveState ppm program on Windows. The following sections describe how to do this.

Perl support for MySQL must be installed if you want to run the MySQL benchmark scripts. See Section 7.1.4, “The MySQL Benchmark Suite”.

#### 2.4.19.1. Installing Perl on Unix

MySQL Perl support requires that you have installed MySQL client programming support (libraries and header files). Most installation methods install the necessary files. However, if you installed MySQL from RPM files on Linux, be sure that you've installed the developer RPM. The client programs are in the client RPM, but client programming support is in the developer RPM.

If you want to install Perl support, the files you need can be obtained from the CPAN (Comprehensive Perl Archive Network) at http://search.cpan.org.

The easiest way to install Perl modules on Unix is to use the `CPAN` module. For example:

    shell> perl -MCPAN -e shell
    cpan> install DBI
    cpan> install DBD::mysql

The `DBD::mysql` installation runs a number of tests. These tests attempt to connect to the local MySQL server using the default username and password. (The default username is your login name on Unix, and `ODBC` on Windows. The default password is “no password.”) If you cannot connect to the server with those values (for example, if your account has a password), the tests fail. You can use `force install DBD::mysql` to ignore the failed tests.

`DBI` requires the `Data::Dumper` module. It may be installed; if not, you should install it before installing `DBI`.

It is also possible to download the module distributions in the form of compressed tar archives and build the modules manually. For example, to unpack and build a DBI distribution, use a procedure such as this:

1. Unpack the distribution into the current directory:

       shell> gunzip < DBI-VERSION.tar.gz | tar xvf -

   This command creates a directory named `DBI-`VERSION``.

2. Change location into the top-level directory of the unpacked distribution:

       shell> cd DBI-VERSION

3. Build the distribution and compile everything:

       shell> perl Makefile.PL
       shell> make
       shell> make test
       shell> make install

The make test command is important because it verifies that the module is working. Note that when you run that command during the `DBD::mysql` installation to exercise the interface code, the MySQL server must be running or the test fails.

It is a good idea to rebuild and reinstall the `DBD::mysql` distribution whenever you install a new release of MySQL, particularly if you notice symptoms such as that all your `DBI` scripts fail after you upgrade MySQL.

If you do not have access rights to install Perl modules in the system directory or if you want to install local Perl modules, the following reference may be useful: http://servers.digitaldaze.com/extensions/perl/modules.html#modules

Look under the heading “Installing New Modules that Require Locally Installed Modules.”

#### 2.4.19.2. Installing ActiveState Perl on Windows

On Windows, you should do the following to install the MySQL `DBD` module with ActiveState Perl:

1. Get ActiveState Perl from http://www.activestate.com/Products/ActivePerl/ and install it.

2. Open a console window (a “DOS window”).

3. If necessary, set the `HTTP_proxy` variable. For example, you might try a setting like this:

       set HTTP_proxy=my.proxy.com:3128

4. Start the PPM program:

       C:\> C:\perl\bin\ppm.pl

5. If you have not previously done so, install `DBI`:

       ppm> install DBI

6. If this succeeds, run the following command:

       ppm> install \
         ftp://ftp.de.uu.net/pub/CPAN/authors/id/JWIED/DBD-mysql-1.2212.x86.ppd

This procedure should work with ActiveState Perl 5.6 or newer.

If you cannot get the procedure to work, you should install the MyODBC driver instead and connect to the MySQL server through ODBC:

    use DBI;
    $dbh= DBI->connect("DBI:ODBC:$dsn",$user,$password) ||
      die "Got error $DBI::errstr when connecting to $dsn\n";

#### 2.4.19.3. Problems Using the Perl `DBI`/`DBD` Interface

If Perl reports that it cannot find the `../mysql/mysql.so` module, the problem is probably that Perl cannot locate the `libmysqlclient.so` shared library. You should be able to fix this problem by one of the following methods:

- Compile the `DBD::mysql` distribution with `perl Makefile.PL -static -config` rather than `perl Makefile.PL`.

- Copy `libmysqlclient.so` to the directory where your other shared libraries are located (probably `/usr/lib` or `/lib`).

- Modify the `-L` options used to compile `DBD::mysql` to reflect the actual location of `libmysqlclient.so`.

- On Linux, you can add the pathname of the directory where `libmysqlclient.so` is located to the `/etc/ld.so.conf` file.

- Add the pathname of the directory where `libmysqlclient.so` is located to the `LD_RUN_PATH` environment variable. Some systems use `LD_LIBRARY_PATH` instead.

Note that you may also need to modify the `-L` options if there are other libraries that the linker fails to find. For example, if the linker cannot find `libc` because it is in `/lib` and the link command specifies `-L/usr/lib`, change the `-L` option to `-L/lib` or add `-L/lib` to the existing link command.

If you get the following errors from `DBD::mysql`, you are probably using gcc (or using an old binary compiled with gcc):

    /usr/bin/perl: can't resolve symbol '__moddi3'
    /usr/bin/perl: can't resolve symbol '__divdi3'

Add `-L/usr/lib/gcc-lib/... -lgcc` to the link command when the `mysql.so` library gets built (check the output from make for `mysql.so` when you compile the Perl client). The `-L` option should specify the pathname of the directory where `libgcc.a` is located on your system.

Another cause of this problem may be that Perl and MySQL are not both compiled with gcc. In this case, you can solve the mismatch by compiling both with gcc.

You may see the following error from `DBD::mysql` when you run the tests:

    t/00base............install_driver(mysql) failed:
    Can't load '../blib/arch/auto/DBD/mysql/mysql.so' for module DBD::mysql:
    ../blib/arch/auto/DBD/mysql/mysql.so: undefined symbol:
    uncompress at /usr/lib/perl5/5.00503/i586-linux/DynaLoader.pm line 169.

This means that you need to include the `-lz` compression library on the link line. That can be done by changing the following line in the file `lib/DBD/mysql/Install.pm`:

    $sysliblist .= " -lm";

Change that line to:

    $sysliblist .= " -lm -lz";

After this, you must run make realclean and then proceed with the installation from the beginning.

If you want to install DBI on SCO, you have to edit the `Makefile` in DBI-`xxx` and each subdirectory. Note that the following assumes gcc 2.95.2 or newer:

    OLD:                                  NEW:
    CC = cc                               CC = gcc
    CCCDLFLAGS = -KPIC -W1,-Bexport       CCCDLFLAGS = -fpic
    CCDLFLAGS = -wl,-Bexport              CCDLFLAGS =

    LD = ld                               LD = gcc -G -fpic
    LDDLFLAGS = -G -L/usr/local/lib       LDDLFLAGS = -L/usr/local/lib
    LDFLAGS = -belf -L/usr/local/lib      LDFLAGS = -L/usr/local/lib

    LD = ld                               LD = gcc -G -fpic
    OPTIMISE = -Od                        OPTIMISE = -O1

    OLD:
    CCCFLAGS = -belf -dy -w0 -U M_XENIX -DPERL_SCO5 -I/usr/local/include

    NEW:
    CCFLAGS = -U M_XENIX -DPERL_SCO5 -I/usr/local/include

These changes are necessary because the Perl dynaloader does not load the `DBI` modules if they were compiled with icc or cc.

If you want to use the Perl module on a system that does not support dynamic linking (such as SCO), you can generate a static version of Perl that includes `DBI` and `DBD::mysql`. The way this works is that you generate a version of Perl with the `DBI` code linked in and install it on top of your current Perl. Then you use that to build a version of Perl that additionally has the `DBD` code linked in, and install that.

On SCO, you must have the following environment variables set:

    LD_LIBRARY_PATH=/lib:/usr/lib:/usr/local/lib:/usr/progressive/lib

Or:

    LD_LIBRARY_PATH=/usr/lib:/lib:/usr/local/lib:/usr/ccs/lib:\
        /usr/progressive/lib:/usr/skunk/lib
    LIBPATH=/usr/lib:/lib:/usr/local/lib:/usr/ccs/lib:\
        /usr/progressive/lib:/usr/skunk/lib
    MANPATH=scohelp:/usr/man:/usr/local1/man:/usr/local/man:\
        /usr/skunk/man:

First, create a Perl that includes a statically linked `DBI` module by running these commands in the directory where your `DBI` distribution is located:

    shell> perl Makefile.PL -static -config
    shell> make
    shell> make install
    shell> make perl

Then you must install the new Perl. The output of make perl indicates the exact make command you need to execute to perform the installation. On SCO, this is make -f Makefile.aperl inst_perl MAP_TARGET=perl.

Next, use the just-created Perl to create another Perl that also includes a statically linked `DBD::mysql` by running these commands in the directory where your `DBD::mysql` distribution is located:

    shell> perl Makefile.PL -static -config
    shell> make
    shell> make install
    shell> make perl

Finally, you should install this new Perl. Again, the output of make perl indicates the command to use.

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