Chapter 5. MySQL Server Administration

Options that affect security: See Section 5.3.3, “Security-Related mysqld Options”.

SSL-related options: See Section 5.5.7.3, “SSL Command Options”.

Binary log control options: See Section 5.2.4, “The Binary Log”.

Replication-related options: See Section 16.1.3, “Replication and Binary Logging Options and Variables”.

Options for loading plugins such as pluggable storage engines: See Section 5.1.3, “Server Options for Loading Plugins”.

Options specific to particular storage engines: See Section 13.5.1, “MyISAM Startup Options”, Section 13.6.3, “InnoDB Startup Options and System Variables”, and mysqld Command Options for MySQL Cluster.

--help, -?

Display a short help message and exit. Use both the --verbose and --help options to see the full message.

--allow-suspicious-udfs

This option controls whether user-defined functions that have only an xxx symbol for the main function can be loaded. By default, the option is off and only UDFs that have at least one auxiliary symbol can be loaded; this prevents attempts at loading functions from shared object files other than those containing legitimate UDFs. See Section 21.3.2.6, “User-Defined Function Security Precautions”.

--ansi

Use standard (ANSI) SQL syntax instead of MySQL syntax. For more precise control over the server SQL mode, use the --sql-mode option instead. See Section 1.7.3, “Running MySQL in ANSI Mode”, and Section 5.1.8, “Server SQL Modes”.

--basedir=path, -b path

The path to the MySQL installation directory. All paths are usually resolved relative to this directory.

--big-tables

Allow large result sets by saving all temporary sets in files. This option prevents most “table full” errors, but also slows down queries for which in-memory tables would suffice. Since MySQL 3.23.2, the server is able to handle large result sets automatically by using memory for small temporary tables and switching to disk tables where necessary.

--bind-address=IP

The IP address to bind to. Only one address can be selected. If this option is specified multiple times, the last address given is used.

If no address or 0.0.0.0 is specified, the server listens on all interfaces.

--binlog-format={ROW|STATEMENT|MIXED}

Specify whether to use row-based, statement-based, or mixed replication. Statement-based is the default in MySQL 5.4. See Section 16.1.2, “Replication Formats”.

--bootstrap

This option is used by the mysql_install_db script to create the MySQL privilege tables without having to start a full MySQL server.

This option is unavailable if MySQL was configured with the --disable-grant-options option. See Section 2.10.2, “Typical configure Options”.

--character-sets-dir=path

The directory where character sets are installed. See Section 9.2, “The Character Set Used for Data and Sorting”.

--character-set-client-handshake

Don't ignore character set information sent by the client. To ignore client information and use the default server character set, use --skip-character-set-client-handshake; this makes MySQL behave like MySQL 4.0.

--character-set-filesystem=charset_name

The file system character set. This option sets the character_set_filesystem system variable.

--character-set-server=charset_name, -C charset_name

Use charset_name as the default server character set. See Section 9.2, “The Character Set Used for Data and Sorting”. If you use this option to specify a nondefault character set, you should also use --collation-server to specify the collation.

--chroot=path, -r path

Put the mysqld server in a closed environment during startup by using the chroot() system call. This is a recommended security measure. Note that use of this option somewhat limits LOAD DATA INFILE and SELECT ... INTO OUTFILE.

--collation-server=collation_name

Use collation_name as the default server collation. See Section 9.2, “The Character Set Used for Data and Sorting”.

--console

(Windows only.) Write error log messages to stderr and stdout even if --log-error is specified. mysqld does not close the console window if this option is used.

--core-file

Write a core file if mysqld dies. The name and location of the core file is system dependent. On Linux, a core file named core.pid is written to the current working directory of the process, which for mysqld is the data directory. pid represents the process ID of the server process. On Mac OS X, a core file named core.pid is written to the /cores directory. On Solaris, use the coreadm command to specify where to write the core file and how to name it.

For some systems, to get a core file you must also specify the --core-file-size option to mysqld_safe. See Section 4.3.2, “mysqld_safe — MySQL Server Startup Script”. On some systems, such as Solaris, you do not get a core file if you are also using the --user option. There might be additional restrictions or limitations. For example, it might be necessary to execute ulimit -c unlimited before starting the server. Consult your system documentation.

--datadir=path, -h path

The path to the data directory.

--debug[=debug_options], -# [debug_options]

If MySQL is configured with --with-debug, you can use this option to get a trace file of what mysqld is doing. A typical debug_options string is 'd:t:o,file_name'. The default is 'd:t:i:o,mysqld.trace'. See MySQL Internals: Porting.

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.

This option may be given multiple times. Values that begin with + or - are added to or subtracted from the previous value. For example, --debug=T --debug=+P sets the value to P:T.

--default-character-set=charset_name (DEPRECATED)