Chapter 4. MySQL Programs

To invoke a MySQL program from the command line (that is, from your shell or command prompt), enter the program name followed by any options or other arguments needed to instruct the program what you want it to do. The following commands show some sample program invocations. "shell>" represents the prompt for your command interpreter; it is not part of what you type. The particular prompt you see depends on your command interpreter. Typical prompts are $ for sh, ksh, or bash, % for csh or tcsh, and C:\> for the Windows command.com or cmd.exe command interpreters.

shell> mysql --user=root testshell> mysqladmin extended-status variablesshell> mysqlshow --helpshell> mysqldump -u root personnel

Arguments that begin with a single or double dash ("-", "--") specify program options. Options typically indicate the type of connection a program should make to the server or affect its operational mode. Option syntax is described in Section 4.2.3, "Specifying Program Options".

Nonoption arguments (arguments with no leading dash) provide additional information to the program. For example, the mysql program interprets the first nonoption argument as a database name, so the command mysql --user=root test indicates that you want to use the test database.

Later sections that describe individual programs indicate which options a program supports and describe the meaning of any additional nonoption arguments.

Some options are common to a number of programs. The most frequently used of these are the --host (or -h), --user (or -u), and --password (or -p) options that specify connection parameters. They indicate the host where the MySQL server is running, and the user name and password of your MySQL account. All MySQL client programs understand these options; they enable you to specify which server to connect to and the account to use on that server. Other connection options are --port (or -P) to specify a TCP/IP port number and --socket (or -S) to specify a Unix socket file on Unix (or named pipe name on Windows). For more information on options that specify connection options, see Section 4.2.2, "Connecting to the MySQL Server".

You may find it necessary to invoke MySQL programs using the path name to the bin directory in which they are installed. This is likely to be the case if you get a "program not found" error whenever you attempt to run a MySQL program from any directory other than the bin directory. To make it more convenient to use MySQL, you can add the path name of the bin directory to your PATH environment variable setting. That enables you to run a program by typing only its name, not its entire path name. For example, if mysql is installed in /usr/local/mysql/bin, you can run the program by invoking it as mysql, and it is not necessary to invoke it as /usr/local/mysql/bin/mysql.

Consult the documentation for your command interpreter for instructions on setting your PATH variable. The syntax for setting environment variables is interpreter-specific. (Some information is given in Section 4.2.4, "Setting Environment Variables".) After modifying your PATH setting, open a new console window on Windows or log in again on Unix so that the setting goes into effect.

For a client program to be able to connect to the MySQL server, it must use the proper connection parameters, such as the name of the host where the server is running and the user name and password of your MySQL account. Each connection parameter has a default value, but you can override them as necessary using program options specified either on the command line or in an option file.

The examples here use the mysql client program, but the principles apply to other clients such as mysqldump, mysqladmin, or mysqlshow.

This command invokes mysql without specifying any connection parameters explicitly:

shell> mysql

Because there are no parameter options, the default values apply:

To specify the host name and user name explicitly, as well as a password, supply appropriate options on the command line:

shell> mysql --host=localhost --user=myname --password=mypass mydbshell> mysql -h localhost -u myname -pmypass mydb

For password options, the password value is optional:

As just mentioned, including the password value on the command line can be a security risk. To avoid this problem, specify the --password or -p option without any following password value:

shell> mysql --host=localhost --user=myname --password mydbshell> mysql -h localhost -u myname -p mydb

When the password option has no password value, the client program prints a prompt and waits for you to enter the password. (In these examples, mydb is not interpreted as a password because it is separated from the preceding password option by a space.)

On some systems, the library routine that MySQL uses to prompt for a password automatically limits the password to eight characters. That is a problem with the system library, not with MySQL. Internally, MySQL does not have any limit for the length of the password. To work around the problem, change your MySQL password to a value that is eight or fewer characters long, or put your password in an option file.

On Unix, MySQL programs treat the host name localhost specially, in a way that is likely different from what you expect compared to other network-based programs. For connections to localhost, MySQL programs attempt to connect to the local server by using a Unix socket file. This occurs even if a --port or -P option is given to specify a port number. To ensure that the client makes a TCP/IP connection to the local server, use --host or -h to specify a host name value of 127.0.0.1, or the IP address or name of the local server. You can also specify the connection protocol explicitly, even for localhost, by using the --protocol=TCP option. For example:

shell> mysql --host=127.0.0.1shell> mysql --protocol=TCP

The --protocol option enables you to establish a particular type of connection even when the other options would normally default to some other protocol.

If the server is configured to accept IPv6 connections, client can connect over IPv6 using --host=::1. See Section 5.1.9, "IPv6 Support".

On Windows, you can force a MySQL client to use a named-pipe connection by specifying the --pipe or --protocol=PIPE option, or by specifying . (period) as the host name. If named-pipe connections are not enabled, an error occurs. Use the --socket option to specify the name of the pipe if you do not want to use the default pipe name.

Connections to remote servers always use TCP/IP. This command connects to the server running on remote.example.com using the default port number (3306):

shell> mysql --host=remote.example.com

To specify a port number explicitly, use the --port or -P option:

shell> mysql --host=remote.example.com --port=13306

You can specify a port number for connections to a local server, too. However, as indicated previously, connections to localhost on Unix will use a socket file by default. You will need to force a TCP/IP connection as already described or any option that specifies a port number will be ignored.

For this command, the program uses a socket file on Unix and the --port option is ignored:

shell> mysql --port=13306 --host=localhost

To cause the port number to be used, invoke the program in either of these ways:

shell> mysql --port=13306 --host=127.0.0.1shell> mysql --port=13306 --protocol=TCP

The following list summarizes the options that can be used to control how client programs connect to the server:

It is possible to specify different default values to be used when you make a connection so that you need not enter them on the command line each time you invoke a client program. This can be done in a couple of ways:

There are several ways to specify options for MySQL programs:

Options are processed in order, so if an option is specified multiple times, the last occurrence takes precedence. The following command causes mysql to connect to the server running on localhost:

shell> mysql -h example.com -h localhost

If conflicting or related options are given, later options take precedence over earlier options. The following command runs mysql in "no column names" mode:

shell> mysql --column-names --skip-column-names

MySQL programs determine which options are given first by examining environment variables, then by reading option files, and then by checking the command line. This means that environment variables have the lowest precedence and command-line options the highest.

You can take advantage of the way that MySQL programs process options by specifying default option values for a program in an option file. That enables you to avoid typing them each time you run the program while enabling you to override the defaults if necessary by using command-line options.

An option can be specified by writing it in full or as any unambiguous prefix. For example, the --compress option can be given to mysqldump as --compr, but not as --comp because the latter is ambiguous:

shell> mysqldump --compmysqldump: ambiguous option '--comp' (compatible, compress)

Be aware that the use of option prefixes can cause problems in the event that new options are implemented for a program. A prefix that is unambiguous now might become ambiguous in the future.

mysql> mysql -u root -p --execute="SELECT User, Host FROM mysql.user"Enter password: ******+------+-----------+| User | Host  |+------+-----------+|  | gigan || root | gigan ||  | localhost || jon  | localhost || root | localhost |+------+-----------+shell>

shell> mysql -u root -p -e "SELECT VERSION();SELECT NOW()"Enter password: ******+-----------------+| VERSION()   |+-----------------+| 5.1.5-alpha-log |+-----------------++---------------------+| NOW()   |+---------------------+| 2006-01-05 21:19:04 |+---------------------+

--disable-column-names--skip-column-names--column-names=0

--column-names--enable-column-names--column-names=1

shell> mysql --loose-no-such-optionmysql: WARNING: unknown option '--no-such-option'

C:\> echo %WINDIR%

basedir="C:\Program Files\MySQL\MySQL Server 5.5"basedir="C:\\Program Files\\MySQL\\MySQL Server 5.5"basedir="C:/Program Files/MySQL/MySQL Server 5.5"basedir=C:\\Program\sFiles\\MySQL\\MySQL\sServer\s5.5

[client]port=3306socket=/tmp/mysql.sock[mysqld]port=3306socket=/tmp/mysql.sockkey_buffer_size=16Mmax_allowed_packet=8M[mysqldump]quick

[client]# The following password will be sent to all standard MySQL clientspassword="my_password"[mysql]no-auto-rehashconnect_timeout=2[mysqlhotcopy]interactive-timeout

[mysqld-5.5]new

!include /home/mydir/myopt.cnf

!includedir /home/mydir

!include /home/mydir/myopt.cnf

[mysqladmin]force[mysqld]key_buffer_size=16M

shell> mysql --max_allowed_packet=16777216shell> mysql --max_allowed_packet=16M

[mysql]max_allowed_packet=16777216

[mysql]max_allowed_packet=16M

[mysqld]key_buffer_size=512M[mysqld]key-buffer-size=512M

shell> mysql --max=1000000mysql: ambiguous option '--max=1000000' (max_allowed_packet, max_join_size)

shell> mysql --max_allowed_packet=16Mshell> mysql --max_allowed_packet=16*1024*1024

mysql> SET GLOBAL max_allowed_packet=16M;mysql> SET GLOBAL max_allowed_packet=16*1024*1024;

shell> mysql --host=tonfisk --user=jon

shell> mysql --host tonfisk --user jon

shell> mysql --host 85.224.35.45 --user jonWelcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 3Server version: 5.5.31 Source distributionType 'help;' or '\h' for help. Type '\c' to clear the buffer.mysql> SELECT CURRENT_USER();+----------------+| CURRENT_USER() |+----------------+| jon@%  |+----------------+1 row in set (0.00 sec)

shell> mysql --host 85.224.35.45 --usermysql: option '--user' requires an argument

shell> mysql --host --user jonERROR 2005 (HY000): Unknown MySQL server host '--user' (1)

shell> mysqld_safe &[1] 11699shell> 080112 12:53:40 mysqld_safe Logging to '/usr/local/mysql/var/tonfisk.err'.080112 12:53:40 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/varshell>

shell> mysqld_safe --log-error &[1] 11699shell> 080112 12:53:40 mysqld_safe Logging to '/usr/local/mysql/var/tonfisk.err'.080112 12:53:40 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/varshell>

shell> mysqld_safe --log-error my-errors &[1] 31357shell> 080111 22:53:31 mysqld_safe Logging to '/usr/local/mysql/var/tonfisk.err'.080111 22:53:32 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/var080111 22:53:34 mysqld_safe mysqld from pid file /usr/local/mysql/var/tonfisk.pid ended[1]+  Done ./mysqld_safe --log-error my-errors

shell> tail /usr/local/mysql/var/tonfisk.err080111 22:53:32  InnoDB: Started; log sequence number 0 46409/usr/local/mysql/libexec/mysqld: Too many arguments (first extra is 'my-errors').Use --verbose --help to get a list of available options080111 22:53:32 [ERROR] Aborting080111 22:53:32  InnoDB: Starting shutdown...080111 22:53:34  InnoDB: Shutdown completed; log sequence number 0 46409080111 22:53:34 [Note] /usr/local/mysql/libexec/mysqld: Shutdown complete080111 22:53:34 mysqld_safe mysqld from pid file /usr/local/mysql/var/tonfisk.pid ended

shell> mysqld_safe --log-error=my-errors &[1] 31437shell> 080111 22:54:15 mysqld_safe Logging to '/usr/local/mysql/var/my-errors.err'.080111 22:54:15 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/varshell>

[mysql]hostuser

shell> mysqlERROR 2005 (HY000): Unknown MySQL server host '--user' (1)

[mysql]user jon

shell> mysqlmysql: unknown option '--user jon'

[mysql]user=jon

shell> mysqlWelcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 5Server version: 5.5.31 Source distributionType 'help;' or '\h' for help. Type '\c' to clear the buffer.mysql> SELECT USER();+---------------+| USER() |+---------------+| jon@localhost |+---------------+1 row in set (0.00 sec)

shell> mysql --user jon --host tonfiskWelcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 6Server version: 5.5.31 Source distributionType 'help;' or '\h' for help. Type '\c' to clear the buffer.mysql> SELECT USER();+---------------+| USER() |+---------------+| jon@tonfisk   |+---------------+1 row in set (0.00 sec)

[mysqld]log_errorrelay_logrelay_log_index

shell> mysqld_safe &090514 09:48:39 mysqld_safe Logging to '/home/jon/bin/mysql-5.5/var/tonfisk.err'.090514 09:48:39 mysqld_safe Starting mysqld daemon with databases from /home/jon/bin/mysql-5.5/var090514 09:48:39 mysqld_safe mysqld from pid file /home/jon/bin/mysql-5.5/var/tonfisk.pid ended

shell> tail -n 3 ../var/tonfisk.err090514 09:48:39 mysqld_safe Starting mysqld daemon with databases from /home/jon/bin/mysql-5.5/var090514  9:48:39 [ERROR] /home/jon/bin/mysql-5.5/libexec/mysqld:  option '--relay-log' requires an argument090514  9:48:39 [ERROR] Aborting

Environment variables can be set at the command prompt to affect the current invocation of your command processor, or set permanently to affect future invocations. To set a variable permanently, you can set it in a startup file or by using the interface provided by your system for this purpose. Consult the documentation for your command interpreter for specific details. Section 2.13, "Environment Variables", lists all environment variables that affect MySQL program operation.

To specify a value for an environment variable, use the syntax appropriate for your command processor. For example, on Windows, you can set the USER variable to specify your MySQL account name. To do so, use this syntax:

SET USER=your_name

The syntax on Unix depends on your shell. Suppose that you want to specify the TCP/IP port number using the MYSQL_TCP_PORT variable. Typical syntax (such as for sh, ksh, bash, zsh, and so on) is as follows:

MYSQL_TCP_PORT=3306export MYSQL_TCP_PORT

The first command sets the variable, and the export command exports the variable to the shell environment so that its value becomes accessible to MySQL and other processes.

For csh and tcsh, use setenv to make the shell variable available to the environment:

setenv MYSQL_TCP_PORT 3306

The commands to set environment variables can be executed at your command prompt to take effect immediately, but the settings persist only until you log out. To have the settings take effect each time you log in, use the interface provided by your system or place the appropriate command or commands in a startup file that your command interpreter reads each time it starts.

On Windows, you can set environment variables using the System Control Panel (under Advanced).

On Unix, typical shell startup files are .bashrc or .bash_profile for bash, or .tcshrc for tcsh.

Suppose that your MySQL programs are installed in /usr/local/mysql/bin and that you want to make it easy to invoke these programs. To do this, set the value of the PATH environment variable to include that directory. For example, if your shell is bash, add the following line to your .bashrc file:

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

bash uses different startup files for login and nonlogin shells, so you might want to add the setting to .bashrc for login shells and to .bash_profile for nonlogin shells to make sure that PATH is set regardless.

If your shell is tcsh, add the following line to your .tcshrc file:

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

If the appropriate startup file does not exist in your home directory, create it with a text editor.

After modifying your PATH setting, open a new console window on Windows or log in again on Unix so that the setting goes into effect.

mysqld, also known as MySQL Server, is the main program that does most of the work in a MySQL installation. MySQL Server manages access to the MySQL data directory that contains databases and tables. The data directory is also the default location for other information such as log files and status files.

When MySQL server starts, it listens for network connections from client programs and manages access to databases on behalf of those clients.

The mysqld program has many options that can be specified at startup. For a complete list of options, run this command:

shell> mysqld --verbose --help

MySQL Server also has a set of system variables that affect its operation as it runs. System variables can be set at server startup, and many of them can be changed at runtime to effect dynamic server reconfiguration. MySQL Server also has a set of status variables that provide information about its operation. You can monitor these status variables to access runtime performance characteristics.

For a full description of MySQL Server command options, system variables, and status variables, see Section 5.1, "The MySQL Server". For information about installing MySQL and setting up the initial configuration, see Chapter 2, Installing and Upgrading MySQL.

mysqld_safe is the recommended way to start a mysqld server on Unix. mysqld_safe adds some safety features such as restarting the server when an error occurs and logging runtime information to an error log file. A description of error logging is given later in this section.

mysqld_safe tries to start an executable named mysqld. To override the default behavior and specify explicitly the name of the server you want to run, specify a --mysqld or --mysqld-version option to mysqld_safe. You can also use --ledir to indicate the directory where mysqld_safe should look for the server.

Many of the options to mysqld_safe are the same as the options to mysqld. See Section 5.1.3, "Server Command Options".

Options unknown to mysqld_safe are passed to mysqld if they are specified on the command line, but ignored if they are specified in the [mysqld_safe] group of an option file. See Section 4.2.3.3, "Using Option Files".

mysqld_safe reads all options from the [mysqld], [server], and [mysqld_safe] sections in option files. For example, if you specify a [mysqld] section like this, mysqld_safe will find and use the --log-error option:

[mysqld]log-error=error.log

For backward compatibility, mysqld_safe also reads [safe_mysqld] sections, although you should rename such sections to [mysqld_safe] in MySQL 5.5 installations.

mysqld_safe supports the following options. It also reads option files and supports the options for processing them described at Section 4.2.3.4, "Command-Line Options that Affect Option-File Handling".

If you execute mysqld_safe with the --defaults-file or --defaults-extra-file option to name an option file, the option must be the first one given on the command line or the option file will not be used. For example, this command will not use the named option file:

mysql> mysqld_safe --port=port_num --defaults-file=file_name

Instead, use the following command:

mysql> mysqld_safe --defaults-file=file_name --port=port_num

The mysqld_safe script is written so that it normally can start a server that was installed from either a source or a binary distribution of MySQL, even though these types of distributions typically install the server in slightly different locations. (See Section 2.1.5, "Installation Layouts".) mysqld_safe expects one of the following conditions to be true:

Because mysqld_safe tries to find the server and databases relative to its own working directory, you can install a binary distribution of MySQL anywhere, as long as you run mysqld_safe from the MySQL installation directory:

shell> cd mysql_installation_directoryshell> bin/mysqld_safe &

If mysqld_safe fails, even when invoked from the MySQL installation directory, you can specify the --ledir and --datadir options to indicate the directories in which the server and databases are located on your system.

Beginning with MySQL 5.5.21, mysqld_safe tries to use the sleep and date system utilities to determine how many times it has attempted to start this second, and-if these are present and this is greater than 5 times-is forced to wait 1 full second before starting again. This is intended to prevent excessive CPU usage in the event of repeated failures. (Bug #11761530, Bug #54035)

When you use mysqld_safe to start mysqld, mysqld_safe arranges for error (and notice) messages from itself and from mysqld to go to the same destination.

There are several mysqld_safe options for controlling the destination of these messages:

If none of these options is given, the default is --skip-syslog.

If --syslog and --log-error are both given, a warning is issued and --log-error takes precedence.

When mysqld_safe writes a message, notices go to the logging destination (syslog or the error log file) and stdout. Errors go to the logging destination and stderr.

Normally, you should not edit the mysqld_safe script. Instead, configure mysqld_safe by using command-line options or options in the [mysqld_safe] section of a my.cnf option file. In rare cases, it might be necessary to edit mysqld_safe to get it to start the server properly. However, if you do this, your modified version of mysqld_safe might be overwritten if you upgrade MySQL in the future, so you should make a copy of your edited version that you can reinstall.

MySQL distributions on Unix include a script named mysql.server. It can be used on systems such as Linux and Solaris that use System V-style run directories to start and stop system services. It is also used by the Mac OS X Startup Item for MySQL.

mysql.server can be found in the support-files directory under your MySQL installation directory or in a MySQL source distribution.

If you use the Linux server RPM package (MySQL-server-VERSION.rpm), the mysql.server script will be installed in the /etc/init.d directory with the name mysql. You need not install it manually. See Section 2.5.1, "Installing MySQL from RPM Packages 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. Instructions are provided in Section 2.11.1.2, "Starting and Stopping MySQL Automatically".

mysql.server reads options from the [mysql.server] and [mysqld] sections of option files. For backward compatibility, it also reads [mysql_server] sections, although you should rename such sections to [mysql.server] when using MySQL 5.5.

mysql.server supports the following options.

mysqld_multi is designed to manage several mysqld processes that listen for connections on different Unix socket files and TCP/IP ports. It can start or stop servers, or report their current status.

mysqld_multi searches for groups named [mysqldN] in my.cnf (or in the file named by the --config-file option). N can be any positive integer. This number is referred to in the following discussion as the option group number, or GNR. Group numbers distinguish option groups from one another and are used as arguments to mysqld_multi to specify which servers you want to start, stop, or obtain a status report for. Options listed in these groups are the same that you would use in the [mysqld] group used for starting mysqld. (See, for example, Section 2.11.1.2, "Starting and Stopping MySQL Automatically".) However, when using multiple servers, it is necessary that each one use its own value for options such as the Unix socket file and TCP/IP port number. For more information on which options must be unique per server in a multiple-server environment, see Section 5.3, "Running Multiple MySQL Instances on One Machine".

To invoke mysqld_multi, use the following syntax:

shell> mysqld_multi [options] {start|stop|report} [GNR[,GNR] ...]

start, stop, and report indicate which operation to perform. You can perform the designated operation for a single server or multiple servers, depending on the GNR list that follows the option name. If there is no list, mysqld_multi performs the operation for all servers in the option file.

Each GNR value represents an option group number or range of group numbers. The value should be the number at the end of the group name in the option file. For example, the GNR for a group named [mysqld17] is 17. To specify a range of numbers, separate the first and last numbers by a dash. The GNR value 10-13 represents groups [mysqld10] through [mysqld13]. Multiple groups or group ranges can be specified on the command line, separated by commas. There must be no whitespace characters (spaces or tabs) in the GNR list; anything after a whitespace character is ignored.

This command starts a single server using option group [mysqld17]:

shell> mysqld_multi start 17

This command stops several servers, using option groups [mysqld8] and [mysqld10] through [mysqld13]:

shell> mysqld_multi stop 8,10-13

For an example of how you might set up an option file, use this command:

shell> mysqld_multi --example

mysqld_multi searches for option files as follows:

Option files read are searched for [mysqld_multi] and [mysqldN] option groups. The [mysqld_multi] group can be used for options to mysqld_multi itself. [mysqldN] groups can be used for options passed to specific mysqld instances.

The [mysqld] or [mysqld_safe] groups can be used for common options read by all instances of mysqld or mysqld_safe. You can specify a --defaults-file=file_name option to use a different configuration file for that instance, in which case the [mysqld] or [mysqld_safe] groups from that file will be used for that instance.

mysqld_multi supports the following options.

Some notes about mysqld_multi:

The following example shows how you might set up an option file for use with mysqld_multi. The order in which the mysqld programs are started or stopped depends on the order in which they appear in the option file. Group numbers need not form an unbroken sequence. The first and fifth [mysqldN] groups were intentionally omitted from the example to illustrate that you can have "gaps" in the option file. This gives you more flexibility.

# This file should probably be in your home dir (~/.my.cnf)# or /etc/my.cnf# Version 2.1 by Jani Tolonen[mysqld_multi]mysqld = /usr/local/bin/mysqld_safemysqladmin = /usr/local/bin/mysqladminuser   = multi_adminpassword   = multipass[mysqld2]socket = /tmp/mysql.sock2port   = 3307pid-file   = /usr/local/mysql/var2/hostname.pid2datadir = /usr/local/mysql/var2language   = /usr/local/share/mysql/englishuser   = john[mysqld3]socket = /tmp/mysql.sock3port   = 3308pid-file   = /usr/local/mysql/var3/hostname.pid3datadir = /usr/local/mysql/var3language   = /usr/local/share/mysql/swedishuser   = monty[mysqld4]socket = /tmp/mysql.sock4port   = 3309pid-file   = /usr/local/mysql/var4/hostname.pid4datadir = /usr/local/mysql/var4language   = /usr/local/share/mysql/estoniauser   = tonu[mysqld6]socket = /tmp/mysql.sock6port   = 3311pid-file   = /usr/local/mysql/var6/hostname.pid6datadir = /usr/local/mysql/var6language   = /usr/local/share/mysql/japaneseuser   = jani

See Section 4.2.3.3, "Using Option Files".

comp_err creates the errmsg.sys file that is used by mysqld to determine the error messages to display for different error codes. comp_err normally is run automatically when MySQL is built. It compiles the errmsg.sys file from the plaintext file located at sql/share/errmsg.txt in MySQL source distributions.

comp_err also generates mysqld_error.h, mysqld_ername.h, and sql_state.h header files.

For more information about how error messages are defined, see the MySQL Internals Manual.

Invoke comp_err like this:

shell> comp_err [options]

comp_err supports the following options.

This program is obsolete.

The normal way to report bugs is to visit http://bugs.mysql.com/, which is the address for our bugs database. This database is public and can be browsed and searched by anyone. If you log in to the system, you can enter new reports.

mysql_install_db initializes the MySQL data directory and creates the system tables that it contains, if they do not exist. mysql_install_db is a shell script and is available only on Unix platforms. (As of MySQL 5.6, mysql_install_db is a Perl script and can be used on any system with Perl installed.)

To invoke mysql_install_db, use the following syntax:

shell> mysql_install_db [options]

Because the MySQL server, mysqld, needs to access the data directory when it runs later, you should either run mysql_install_db from the same system account that will be used for running mysqld or run it as root and use the --user option to indicate the user name that mysqld will run as. It might be necessary to specify other options such as --basedir or --datadir if mysql_install_db does not use the correct locations for the installation directory or data directory. For example:

shell> scripts/mysql_install_db --user=mysql \ --basedir=/opt/mysql/mysql \ --datadir=/opt/mysql/mysql/data

mysql_install_db needs to invoke mysqld with the --bootstrap and --skip-grant-tables options. If MySQL was configured with the DISABLE_GRANT_OPTIONS compiler flag, --bootstrap and --skip-grant-tables will be disabled (see Section 2.10.4, "MySQL Source-Configuration Options"). To handle this, set the MYSQLD_BOOTSTRAP environment variable to the full path name of a server that has all options enabled. mysql_install_db will use that server.

mysql_install_db supports the following options, which can be specified on the command line or in the [mysql_install_db] group of an option file. (Options that are common to mysqld can also be specified in the [mysqld] group.) Other options are passed to mysqld. For information about option files, see Section 4.2.3.3, "Using Option Files". mysql_install_db also supports the options for processing option files described at Section 4.2.3.4, "Command-Line Options that Affect Option-File Handling".

The mysql_plugin utility enables MySQL administrators to manage which plugins a MySQL server loads. It provides an alternative to manually specifying the --plugin-load option at server startup or using the INSTALL PLUGIN and UNINSTALL PLUGIN statements at runtime. mysql_plugin is available as of MySQL 5.5.16.

Depending on whether mysql_plugin is invoked to enable or disable plugins, it inserts or deletes rows in the mysql.plugin table that serves as a plugin registry. (To perform this operation, mysql_plugin invokes the MySQL server in bootstrap mode. This means that the server must not already be running.) For normal server startups, the server loads and enables plugins listed in mysql.plugin automatically. For additional control over plugin activation, use --plugin_name options named for specific plugins, as described in Section 5.1.8.1, "Installing and Uninstalling Plugins".

Each invocation of mysql_plugin reads a configuration file to determine how to configure the plugins contained in a single plugin library object file. To invoke mysql_plugin, use this syntax:

mysql_plugin [options] plugin {ENABLE|DISABLE}

plugin is the name of the plugin to configure. ENABLE or DISABLE (not case sensitive) specify whether to enable or disable components of the plugin library named in the configuration file. The order of the plugin and ENABLE or DISABLE arguments does not matter.

For example, to configure components of a plugin library file named myplugins.so on Linux or myplugins.dll on Windows, specify a plugin value of myplugins. Suppose that this plugin library contains three plugins, plugin1, plugin2, and plugin3, all of which should be configured under mysql_plugin control. By convention, configuration files have a suffix of .ini and the same basename as the plugin library, so the default configuration file name for this plugin library is myplugins.ini. The configuration file contents look like this:

mypluginsplugin1plugin2plugin3

The first line in the myplugins.ini file is the name of the library object file, without any extension such as .so or .dll. The remaining lines are the names of the components to be enabled or disabled. Each value in the file should be on a separate line. Lines on which the first character is '#' are taken as comments and ignored.

To enable the plugins listed in the configuration file, invoke mysql_plugin this way:

shell> mysql_plugin myplugins ENABLE

To disable the plugins, use DISABLE rather than ENABLE.

An error occurs if mysql_plugin cannot find the configuration file or plugin library file, or if mysql_plugin cannot start the MySQL server.

mysql_plugin supports the following options, which can be specified on the command line or in the [mysqld] group of any option file. For options specified in a [mysqld] group, mysql_plugin recognizes the --basedir, --datadir, and --plugin-dir options and ignores others. For information about option files, see Section 4.2.3.3, "Using Option Files".

mysql_plugin Options

This program enables you to improve the security of your MySQL installation in the following ways:

mysql_secure_installation helps you implement security recommendations similar to those described at Section 2.11.2, "Securing the Initial MySQL Accounts".

Invoke mysql_secure_installation without arguments:

shell> mysql_secure_installation

The script will prompt you to determine which actions to perform.

mysql_secure_installation is not available on Windows.

The mysql_tzinfo_to_sql program loads the time zone tables in the mysql database. It is used on systems that have a zoneinfo database (the set of files describing time zones). Examples of such systems are Linux, FreeBSD, Solaris, and Mac OS X. One likely location for these files is the /usr/share/zoneinfo directory (/usr/share/lib/zoneinfo on Solaris). If your system does not have a zoneinfo database, you can use the downloadable package described in Section 10.6, "MySQL Server Time Zone Support".

mysql_tzinfo_to_sql can be invoked several ways:

shell> mysql_tzinfo_to_sql tz_dirshell> mysql_tzinfo_to_sql tz_file tz_nameshell> mysql_tzinfo_to_sql --leap tz_file

For the first invocation syntax, pass the zoneinfo directory path name to mysql_tzinfo_to_sql and send the output into the mysql program. For example:

shell> mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root mysql

mysql_tzinfo_to_sql reads your system's time zone files and generates SQL statements from them. mysql processes those statements to load the time zone tables.

The second syntax causes mysql_tzinfo_to_sql to load a single time zone file tz_file that corresponds to a time zone name tz_name:

shell> mysql_tzinfo_to_sql tz_file tz_name | mysql -u root mysql

If your time zone needs to account for leap seconds, invoke mysql_tzinfo_to_sql using the third syntax, which initializes the leap second information. tz_file is the name of your time zone file:

shell> mysql_tzinfo_to_sql --leap tz_file | mysql -u root mysql

After running mysql_tzinfo_to_sql, it is best to restart the server so that it does not continue to use any previously cached time zone data.

mysql_upgrade examines all tables in all databases for incompatibilities with the current version of MySQL Server. mysql_upgrade also upgrades the system tables so that you can take advantage of new privileges or capabilities that might have been added.

mysql_upgrade should be executed each time you upgrade MySQL.

If mysql_upgrade finds that a table has a possible incompatibility, it performs a table check and, if problems are found, attempts a table repair. If the table cannot be repaired, see Section 2.12.4, "Rebuilding or Repairing Tables or Indexes" for manual table repair strategies.

To use mysql_upgrade, make sure that the server is running, and then invoke it like this:

shell> mysql_upgrade [options]

After running mysql_upgrade, stop the server and restart it so that any changes made to the system tables take effect.

mysql_upgrade executes the following commands to check and repair tables and to upgrade the system tables:

mysqlcheck --all-databases --check-upgrade --auto-repairmysql < fix_priv_tablesmysqlcheck --all-databases --check-upgrade --fix-db-names --fix-table-names

Notes about the preceding commands:

All checked and repaired tables are marked with the current MySQL version number. This ensures that next time you run mysql_upgrade with the same version of the server, it can tell whether there is any need to check or repair the table again.

mysql_upgrade also saves the MySQL version number in a file named mysql_upgrade_info in the data directory. This is used to quickly check whether all tables have been checked for this release so that table-checking can be skipped. To ignore this file and perform the check regardless, use the --force option.

If you install MySQL from RPM packages on Linux, you must install the server and client RPMs. mysql_upgrade is included in the server RPM but requires the client RPM because the latter includes mysqlcheck. (See Section 2.5.1, "Installing MySQL from RPM Packages on Linux".)

mysql_upgrade does not upgrade the contents of the help tables. For upgrade instructions, see Section 5.1.10, "Server-Side Help".

mysql_upgrade supports the following options, which can be specified on the command line or in the [mysql_upgrade] and [client] groups of an option file. Other options are passed to mysqlcheck. For example, it might be necessary to specify the --password[=password] option. mysql_upgrade also supports the options for processing option files described at Section 4.2.3.4, "Command-Line Options that Affect Option-File Handling".