The default hostname is localhost. On Unix, this has a special meaning, as described later.

The default username is ODBC on Windows or your Unix login name on Unix.

No password is sent if neither -p nor --password is given.

If you use a -p or --password option but do not specify the password value, the client program prompts you to enter the password. The password is not displayed as you enter it. This is more secure than giving the password on the command line. Any user on your system may be able to see a password specified on the command line by executing a command such as ps auxw. See Section 5.5.6, “Keeping Your Password Secure”.

If you use a -p or --password option and do specify the password value, there must be no space between -p or --password= and the password following it.

--host=host_name, -h host_name

The host where the server is running. The default value is localhost.

--password[=pass_val], -p[pass_val]

The password of the MySQL account. As described earlier, the password value is optional, but if given, there must be no space between -p or --password= and the password following it. The default is to send no password.

--pipe, -W

On Windows, connect to the server via a named pipe. This option applies for connections to a local server only. The server must have been started with the --enable-named-pipe option to enable named-pipe connections.

--port=port_num, -P port_num

The port number to use for the connection, for connections made via TCP/IP. The default port number is 3306.

--protocol={TCP|SOCKET|PIPE|MEMORY}

This option explicitly specifies a protocol to use for connecting to the server. It is useful when the other connection parameters normally would cause a protocol to be used other than the one you want. For example, connections on Unix to localhost are made via a Unix socket file by default:

shell> mysql --host=localhost

To force a TCP/IP connection to be used instead, specify a --protocol option:

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

The following table shows the allowable --protocol option values and indicates the platforms on which each value may be used. The values are not case sensitive.

--shared-memory-base-name=name

On Windows, the shared-memory name to use, for connections made via shared memory to a local server. The default value is MYSQL. The shared-memory name is case sensitive.

The server must be started with the --shared-memory option to enable shared-memory connections.

--socket=file_name, -S file_name

On Unix, the name of the Unix socket file to use, for connections made via a named pipe to a local server. The default Unix socket filename is /tmp/mysql.sock.

On Windows, the name of the named pipe to use, for connections to a local server. The default Windows pipe name is MySQL. The pipe name is not case sensitive.

The server must be started with the --enable-named-pipe option to enable named-pipe connections.

--ssl*

Options that begin with --ssl are used for establishing a secure connection to the server via SSL, if the server is configured with SSL support. For details, see Section 5.5.7.3, “SSL Command Options”.

--user=user_name, -u user_name

The username of the MySQL account you want to use. The default username is ODBC on Windows or your Unix login name on Unix.

You can specify connection parameters in the [client] section of an option file. The relevant section of the file might look like this:

[client]
host=host_name
user=user_name
password=your_pass

Section 4.2.3.2, “Using Option Files”, discusses option files further.

You can specify some connection parameters using environment variables. The host can be specified for mysql using MYSQL_HOST. The MySQL username can be specified using USER (this is for Windows and NetWare only). The password can be specified using MYSQL_PWD, although this is insecure; see Section 5.5.6, “Keeping Your Password Secure”. For a list of variables, see Section 2.4.20, “Environment Variables”.

List the options on the command line following the program name. This is most common for options that apply to a specific invocation of the program.

List the options in an option file that the program reads when it starts. This is common for options that you want the program to use each time it runs.

List the options in environment variables (see Section 4.2.4, “Setting Environment Variables”). This method is useful for options that you want to apply each time the program runs. In practice, option files are used more commonly for this purpose, but Section 5.6.2, “Running Multiple Servers on Unix”, discusses one situation in which environment variables can be very helpful. It describes a handy technique that uses such variables to specify the TCP/IP port number and Unix socket file for the server and for client programs.

On Linux, the MySQL-Max RPM relies on this mysqld_safe behavior. The RPM installs an executable named mysqld-max, which causes mysqld_safe to automatically use that executable rather than mysqld from that point on.

If you install a MySQL-Max distribution that includes a server named mysqld-max, and then upgrade later to a non-Max version of MySQL, mysqld_safe will still attempt to run the old mysqld-max server. If you perform such an upgrade, you should manually remove the old mysqld-max server to ensure that mysqld_safe runs the new mysqld server.

--help

Display a help message and exit. (Added in MySQL 5.0.3)

--autoclose

(NetWare only) On NetWare, mysqld_safe provides a screen presence. When you unload (shut down) the mysqld_safe NLM, the screen does not by default go away. 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.

--basedir=path

The path to the MySQL installation directory.

--core-file-size=size

The size of the core file that mysqld should be able to create. The option value is passed to ulimit -c.

--datadir=path

The path to the data directory.

--defaults-extra-file=path

The name of an option file to be read in addition to the usual option files. This must be the first option on the command line if it is used. As of MySQL 5.0.6, if the file does not exist or is otherwise inaccessible, the server will exit with an error.

--defaults-file=file_name

The name of an option file to be read instead of the usual option files. This must be the first option on the command line if it is used.

--ledir=path

If mysqld_safe cannot find the server, use this option to indicate the pathname to the directory where the server is located.

--log-error=file_name

Write the error log to the given file. See Section 5.2.1, “The Error Log”.

--mysqld=prog_name

The name of the server program (in the ledir directory) that you want to start. This option is needed if you use the MySQL binary distribution but have the data directory outside of the binary distribution. If mysqld_safe cannot find the server, use the --ledir option to indicate the pathname to the directory where the server is located.

--mysqld-version=suffix

This option is similar to the --mysqld option, but you specify only the suffix for the server program name. The basename is assumed to be mysqld. For example, if you use --mysqld-version=debug, mysqld_safe starts the mysqld-debug program in the ledir directory. If the argument to --mysqld-version is empty, mysqld_safe uses mysqld in the ledir directory.

--nice=priority

Use the nice program to set the server's scheduling priority to the given value.

--no-defaults

Do not read any option files. This must be the first option on the command line if it is used.

--open-files-limit=count

The number of files that mysqld should be able to open. The option value is passed to ulimit -n. Note that you need to start mysqld_safe as root for this to work properly!

--pid-file=file_name

The pathname of the process ID file.

--port=port_num

The port number that the server should use when listening for TCP/IP connections. The port number must be 1024 or higher unless the server is started by the root system user.

--skip-kill-mysqld

Do not try to kill stray mysqld processes at startup. This option works only on Linux.

--socket=path

The Unix socket file that the server should use when listening for local connections.

--timezone=timezone

Set the TZ time zone environment variable to the given option value. Consult your operating system documentation for legal time zone specification formats.

--user={user_name|user_id}

Run the mysqld server as the user having the name user_name or the numeric user ID user_id. (“User” in this context refers to a system login account, not a MySQL user listed in the grant tables.)

The server and databases can be found relative to the working directory (the directory from which mysqld_safe is invoked). For binary distributions, mysqld_safe looks under its working directory for bin and data directories. For source distributions, it looks for libexec and var directories. This condition should be met if you execute mysqld_safe from your MySQL installation directory (for example, /usr/local/mysql for a binary distribution).

If the server and databases cannot be found relative to the working directory, mysqld_safe attempts to locate them by absolute pathnames. Typical locations are /usr/local/libexec and /usr/local/var. The actual locations are determined from the values configured into the distribution at the time it was built. They should be correct if MySQL is installed in the location specified at configuration time.

--basedir=path

The path to the MySQL installation directory.

--datadir=path

The path to the MySQL data directory.

--pid-file=file_name

The pathname of the file in which the server should write its process ID.

--service-startup-timeout=file_name

How long in seconds to wait for confirmation of server startup. If the server does not start within this time, mysql.server exits with an error. The default value is 900. A value of 0 means not to wait at all for startup. Negative values mean to wait forever (no timeout). This option was added in MySQL 5.0.40. Before that, a value of 900 is always used.

--use-mysqld_safe

Use mysqld_safe to start the server. This is the default. This option was added in MySQL 5.0.4.

--use-manager

Use Instance Manager to start the server. This option was added in MySQL 5.0.4.

--user=user_name

The login username to use for running mysqld. This option was added in MySQL 5.0.4.

With --no-defaults, no option files are read.

With --defaults-file=file_name, only the named file is read.

Otherwise, option files in the standard list of locations are read, including any file named by the --defaults-extra-file=file_name option, if one is given. (If the option is given multiple times, the last value is used.)

--help

Display a help message and exit.

--config-file=file_name

As of MySQL 5.0.42, this option is deprecated. If given, it is treated the same way as --defaults-extra-file, described earlier.

Before MySQL 5.0.42, this option specifies the name of an extra option file. It affects where mysqld_multi looks for [mysqldN] option groups. Without this option, all options are read from the usual my.cnf file. The option does not affect where mysqld_multi reads its own options, which are always taken from the [mysqld_multi] group in the usual my.cnf file.

--example

Display a sample option file.

--log=file_name

Specify the name of the log file. If the file exists, log output is appended to it.

--mysqladmin=prog_name

The mysqladmin binary to be used to stop servers.

--mysqld=prog_name

The mysqld binary to be used. Note that you can specify mysqld_safe as the value for this option also. If you use mysqld_safe to start the server, you can include the mysqld or ledir options in the corresponding [mysqldN] option group. These options indicate the name of the server that mysqld_safe should start and the pathname of the directory where the server is located. (See the descriptions for these options in Section 4.3.2, “mysqld_safe — MySQL Server Startup Script”.) Example:

[mysqld38]
mysqld = mysqld-debug
ledir  = /opt/local/mysql/libexec

--no-log

Print log information to stdout rather than to the log file. By default, output goes to the log file.

--password=password

The password of the MySQL account to use when invoking mysqladmin. Note that the password value is not optional for this option, unlike for other MySQL programs.

--silent

Silent mode; disable warnings.

--tcp-ip

Connect to each MySQL server via the TCP/IP port instead of the Unix socket file. (If a socket file is missing, the server might still be running, but accessible only via the TCP/IP port.) By default, connections are made using the Unix socket file. This option affects stop and report operations.

--user=user_name

The username of the MySQL account to use when invoking mysqladmin.

--verbose

Be more verbose.

--version

Display version information and exit.

Most important: Before using mysqld_multi be sure that you understand the meanings of the options that are passed to the mysqld servers and why you would want to have separate mysqld processes. Beware of the dangers of using multiple mysqld servers with the same data directory. Use separate data directories, unless you know what you are doing. Starting multiple servers with the same data directory does not give you extra performance in a threaded system. See Section 5.6, “Running Multiple MySQL Servers on the Same Machine”.

Make sure that the MySQL account used for stopping the mysqld servers (with the mysqladmin program) has the same username and password for each server. Also, make sure that the account has the SHUTDOWN privilege. If the servers that you want to manage have different usernames or passwords for the administrative accounts, you might want to create an account on each server that has the same username and password. For example, you might set up a common multi_admin account by executing the following commands for each server:

shell> mysql -u root -S /tmp/mysql.sock -p
Enter password:
mysql> GRANT SHUTDOWN ON *.*
    -> TO 'multi_admin'@'localhost' IDENTIFIED BY 'multipass';

See Section 5.4.2, “How the Privilege System Works”. You have to do this for each mysqld server. Change the connection parameters appropriately when connecting to each one. Note that the hostname part of the account name must allow you to connect as multi_admin from the host where you want to run mysqld_multi.

The Unix socket file and the TCP/IP port number must be different for every mysqld. (Alternatively, if the host has multiple network addresses, you can use --bind-adress to cause different servers to listen to different interfaces.)

The --pid-file option is very important if you are using mysqld_safe to start mysqld (for example, --mysqld=mysqld_safe) Every mysqld should have its own process ID file. The advantage of using mysqld_safe instead of mysqld is that mysqld_safe monitors its mysqld process and restarts it if the process terminates due to a signal sent using kill -9 or for other reasons, such as a segmentation fault. Please note that the mysqld_safe script might require that you start it from a certain place. This means that you might have to change location to a certain directory before running mysqld_multi. If you have problems starting, please see the mysqld_safe script. Check especially the lines:

----------------------------------------------------------------
MY_PWD=`pwd`
# Check if we are starting this relative (for the binary release)
if test -d $MY_PWD/data/mysql -a -f ./share/mysql/english/errmsg.sys -a \
 -x ./bin/mysqld
----------------------------------------------------------------

The test performed by these lines should be successful, or you might encounter problems. See Section 4.3.2, “mysqld_safe — MySQL Server Startup Script”.

You might want to use the --user option for mysqld, but to do this you need to run the mysqld_multi script as the Unix root user. Having the option in the option file doesn't matter; you just get a warning if you are not the superuser and the mysqld processes are started under your own Unix account.

--help, -?

Display a help message and exit.

--charset=path, -C path

The character set directory. The default is ../sql/share/charsets.

--debug=debug_options, -# debug_options

Write a debugging log. The debug_options string often is 'd:t:O,file_name'. The default is 'd:t:O,/tmp/comp_err.trace'.

--debug-info, -T

Print some debugging information when the program exits.

--header_file=file_name, -H file_name

The name of the error header file. The default is mysqld_error.h.

--in_file=file_name, -F file_name

The name of the input file. The default is ../sql/share/errmsg.txt.

--name_file=file_name, -N file_name

The name of the error name file. The default is mysqld_ername.h.

--out_dir=path, -D path

The name of the output base directory. The default is ../sql/share/.

--out_file=file_name, -O file_name

The name of the output file. The default is errmsg.sys.

--statefile=file_name, -S file_name

The name for the SQLSTATE header file. The default is sql_state.h.

--version, -V

Display version information and exit.

--debug

Pack the debug binaries and produce an error if they were not built.

--embedded

Pack the embedded server and produce an error if it was not built. The default is to pack it if it was built.

--exe-suffix=suffix

Add a suffix to the basename of the mysql binary. For example, a suffix of -abc produces a binary named mysqld-abc.exe.

--no-debug

Don't pack the debug binaries even if they were built.

--no-embedded

Don't pack the embedded server even if it was built.

--only-debug

Use this option when the target for this build was Debug, and you just want to replace the normal binaries with debug versions (that is, do not use separate debug directories).

--help

Display a help message and exit.

--debug

Print information about script operations; do not create a 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 a tar.gz package instead of a .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.

--basedir=path

The path to the MySQL installation directory.

--force

Causes mysql_install_db to run even if DNS does not work. In that case, grant table entries that normally use hostnames will use IP addresses.

--datadir=path, --ldata=path

The path to the MySQL data directory.

--rpm

For internal use. This option is used by RPM files during the MySQL installation process.

--skip-name-resolve

Use IP addresses rather than hostnames when creating grant table entries. This option can be useful if your DNS does not work.

--srcdir=path

For internal use. The directory under which mysql_install_db looks for support files such as the error message file and the file for populating the help tables. This option was added in MySQL 5.0.32.

--user=user_name

The login username to use for running mysqld. Files and directories created by mysqld will be owned by this user. You must be root to use this option. By default, mysqld runs using your current login name and files and directories that it creates will be owned by you.

--verbose

Verbose mode. Print more information about what the program does.

--windows

For internal use. This option is used for creating Windows distributions.

You can set a password for root accounts.

You can remove root accounts that are accessible from outside the local host.

You can remove anonymous-user accounts.

You can remove the test database, which by default can be accessed by anonymous users.

--help

Display a short help message and exit.

--basedir=path

The path to the MySQL installation directory.

--datadir=path

The path to the data directory.

--force

Force execution of mysqlcheck even if mysql_upgrade has already been executed for the current version of MySQL. (In other words, this option causes the mysql_upgrade_info file to be ignored.)

--tmpdir=path, -t path

The pathname of the directory to use for creating temporary files. This option was added in MySQL 5.0.62.

--user=user_name, -u user_name

The MySQL username to use when connecting to the server. The default username is root.

--verbose

Verbose mode. Print more information about what the program does.

create db_name

Create a new database named db_name.

debug

Tell the server to write debug information to the error log.

drop db_name

Delete the database named db_name and all its tables.

extended-status

Display the server status variables and their values.

MySQL Enterprise For expert advice on using server status variables, subscribe to the MySQL Enterprise Monitor. For more information see http://www.mysql.com/products/enterprise/advisors.html.

flush-hosts

Flush all information in the host cache.

flush-logs

Flush all logs.

flush-privileges

Reload the grant tables (same as reload).

flush-status

Clear status variables.

flush-tables

Flush all tables.

flush-threads

Flush the thread cache.

kill id,id,...

Kill server threads. If multiple thread ID values are given, there must be no spaces in the list.

old-password new-password

This is like the password command but stores the password using the old (pre-4.1) password-hashing format. (See Section 5.4.8, “Password Hashing as of MySQL 4.1”.)

MySQL Enterprise For expert advice on the security implications of using the old-password command, subscribe to the MySQL Enterprise Monitor. For more information, see http://www.mysql.com/products/enterprise/advisors.html.

password new-password

Set a new password. This changes the password to new-password for the account that you use with mysqladmin for connecting to the server. Thus, the next time you invoke mysqladmin (or any other client program) using the same account, you will need to specify the new password.

If the new-password value contains spaces or other characters that are special to your command interpreter, you need to enclose it within quotes. On Windows, be sure to use double quotes rather than single quotes; single quotes are not stripped from the password, but rather are interpreted as part of the password. For example:

shell> mysqladmin password "my new password"

ping

Check whether the server is alive. The return status from mysqladmin is 0 if the server is running, 1 if it is not. This is 0 even in case of an error such as Access denied, because this means that the server is running but refused the connection, which is different from the server not running.

processlist

Show a list of active server threads. This is like the output of the SHOW PROCESSLIST statement. If the --verbose option is given, the output is like that of SHOW FULL PROCESSLIST. (See Section 12.5.5.24, “SHOW PROCESSLIST Syntax”.)

reload

Reload the grant tables.

refresh

Flush all tables and close and open log files.

shutdown

Stop the server.

start-slave

Start replication on a slave server.

status

Display a short server status message.

stop-slave

Stop replication on a slave server.

variables

Display the server system variables and their values.

MySQL Enterprise For expert advice on using server system variables, subscribe to the MySQL Enterprise Monitor. For more information see http://www.mysql.com/products/enterprise/advisors.html.

version

Display version information from the server.

Uptime

The number of seconds the MySQL server has been running.

Threads

The number of active threads (clients).

Questions

The number of questions (queries) from clients since the server was started.

Slow queries

The number of queries that have taken more than long_query_time seconds. See Section 5.2.4, “The Slow Query Log”.

Opens

The number of tables the server has opened.

Flush tables

The number of flush-*, refresh, and reload commands the server has executed.

Open tables

The number of tables that currently are open.

Memory in use

The amount of memory allocated directly by mysqld. This value is displayed only when MySQL has been compiled with --with-debug=full.

Maximum memory used

The maximum amount of memory allocated directly by mysqld. This value is displayed only when MySQL has been compiled with --with-debug=full.

--help, -?

Display a help message and exit.

--character-sets-dir=path

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

--compress, -C

Compress all information sent between the client and the server if both support compression.

--count=N, -c N

The number of iterations to make for repeated command execution if the --sleep option is given.

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

Write a debugging log. The debug_options string often is 'd:t:o,file_name'. The default is 'd:t:o,/tmp/mysqladmin.trace'.

--default-character-set=charset_name

Use charset_name as the default character set. See Section 9.2, “The Character Set Used for Data and Sorting”.

--force, -f

Do not ask for confirmation for the drop db_name command. With multiple commands, continue even if an error occurs.

--host=host_name, -h host_name

Connect to the MySQL server on the given host.

--password[=password], -p[password]

The password to use when connecting to the server. If you use the short option form (-p), you cannot have a space between the option and the password. If you omit the password value following the --password or -p option on the command line, you are prompted for one.

Specifying a password on the command line should be considered insecure. See Section 5.5.6, “Keeping Your Password Secure”.

--pipe, -W

On Windows, connect to the server via a named pipe. This option applies only for connections to a local server, and only if the server supports named-pipe connections.

--port=port_num, -P port_num

The TCP/IP port number to use for the connection.

--protocol={TCP|SOCKET|PIPE|MEMORY}

The connection protocol to use for connecting to the server. It is useful when the other connection parameters normally would cause a protocol to be used other than the one you want. For details on the allowable values, see Section 4.2.2, “Connecting to the MySQL Server”.

--relative, -r

Show the difference between the current and previous values when used with the --sleep option. Currently, this option works only with the extended-status command.

--silent, -s

Exit silently if a connection to the server cannot be established.

--sleep=delay, -i delay

Execute commands repeatedly, sleeping for delay seconds in between. The --count option determines the number of iterations. If --count is not given, mysqladmin executes commands indefinitely until interrupted.

--socket=path, -S path

For connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use.

--ssl*

Options that begin with --ssl specify whether to connect to the server via SSL and indicate where to find SSL keys and certificates. See Section 5.5.7.3, “SSL Command Options”.

--user=user_name, -u user_name

The MySQL username to use when connecting to the server.

--verbose, -v

Verbose mode. Print more information about what the program does.

--version, -V

Display version information and exit.

--vertical, -E

Print output vertically. This is similar to --relative, but prints output vertically.

--wait[=count], -w[count]

If the connection cannot be established, wait and retry instead of aborting. If a count value is given, it indicates the number of times to retry. The default is one time.

connect_timeout

The maximum number of seconds before connection timeout. The default value is 43200 (12 hours).

shutdown_timeout

The maximum number of seconds to wait for server shutdown. The default value is 3600 (1 hour).

--help, -?

Display a help message and exit.

--all-databases, -A

Check all tables in all databases. This is the same as using the --databases option and naming all the databases on the command line.

--all-in-1, -1

Instead of issuing a statement for each table, execute a single statement for each database that names all the tables from that database to be processed.

--analyze, -a

Analyze the tables.

MySQL Enterprise For expert advice on optimizing tables, subscribe to the MySQL Enterprise Monitor. For more information, see http://www.mysql.com/products/enterprise/advisors.html.

--auto-repair

If a checked table is corrupted, automatically fix it. Any necessary repairs are done after all tables have been checked.

--character-sets-dir=path

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

--check, -c

Check the tables for errors. This is the default operation.

--check-only-changed, -C

Check only tables that have changed since the last check or that have not been closed properly.

--check-upgrade, -g

Invoke CHECK TABLE with the FOR UPGRADE option to check tables for incompatibilities with the current version of the server. This option was added in MySQL 5.0.19.

--compress

Compress all information sent between the client and the server if both support compression.

--databases, -B

Process all tables in the named databases. Normally, mysqlcheck treats the first name argument on the command line as a database name and following names as table names. With this option, it treats all name arguments as database names.

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

Write a debugging log. A typical debug_options string is often 'd:t:o,file_name'.

--default-character-set=charset_name

Use charset_name as the default character set. See Section 9.2, “The Character Set Used for Data and Sorting”.

--extended, -e

If you are using this option to check tables, it ensures that they are 100% consistent but takes a long time.

If you are using this option to repair tables, it runs an extended repair that may not only take a long time to execute, but may produce a lot of garbage rows also!

--fast, -F

Check only tables that have not been closed properly.

--force, -f

Continue even if an SQL error occurs.

--host=host_name, -h host_name

Connect to the MySQL server on the given host.

--medium-check, -m

Do a check that is faster than an --extended operation. This finds only 99.99% of all errors, which should be good enough in most cases.

--optimize, -o

Optimize the tables.

--password[=password], -p[password]

The password to use when connecting to the server. If you use the short option form (-p), you cannot have a space between the option and the password. If you omit the password value following the --password or -p option on the command line, you are prompted for one.

Specifying a password on the command line should be considered insecure. See Section 5.5.6, “Keeping Your Password Secure”.

--pipe, -W

On Windows, connect to the server via a named pipe. This option applies only for connections to a local server, and only if the server supports named-pipe connections.

--port=port_num, -P port_num

The TCP/IP port number to use for the connection.

--protocol={TCP|SOCKET|PIPE|MEMORY}

The connection protocol to use for connecting to the server. It is useful when the other connection parameters normally would cause a protocol to be used other than the one you want. For details on the allowable values, see Section 4.2.2, “Connecting to the MySQL Server”.

--quick, -q

If you are using this option to check tables, it prevents the check from scanning the rows to check for incorrect links. This is the fastest check method.

If you are using this option to repair tables, it tries to repair only the index tree. This is the fastest repair method.

--repair, -r

Perform a repair that can fix almost anything except unique keys that are not unique.

--silent, -s

Silent mode. Print only error messages.

--socket=path, -S path

For connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use.

--ssl*

Options that begin with --ssl specify whether to connect to the server via SSL and indicate where to find SSL keys and certificates. See Section 5.5.7.3, “SSL Command Options”.

--tables

Overrides the --databases or -B option. All name arguments following the option are regarded as table names.

--use-frm

For repair operations on MyISAM tables, get the table structure from the .frm file so that the table can be repaired even if the .MYI header is corrupted.

--user=user_name, -u user_name

The MySQL username to use when connecting to the server.

--verbose, -v

Verbose mode. Print information about the various stages of program operation.

--version, -V

Display version information and exit.

To select the effect of --opt except for some features, use the --skip option for each feature. For example, to disable extended inserts and memory buffering, use --opt --skip-extended-insert --skip-quick. (As of MySQL 5.0, --skip-extended-insert --skip-quick is sufficient because --opt is on by default.)

To reverse --opt for all features except index disabling and table locking, use --skip-opt --disable-keys --lock-tables.