mysqlcheck(1) — Linux manual page


MARIADB-CHECK(1)         MariaDB Database System        MARIADB-CHECK(1)

NAME         top

       mariadb-check - a table maintenance program (mysqlcheck is now a
       symlink to mariadb-check)

SYNOPSIS         top

       mysqlcheck [options] [db_name [tbl_name ...]]

DESCRIPTION         top

       The mysqlcheck client performs table maintenance: It checks,
       repairs, optimizes, or analyzes tables.

       Each table is locked and therefore unavailable to other sessions
       while it is being processed, although for check operations, the
       table is locked with a READ lock only. Table maintenance
       operations can be time-consuming, particularly for large tables.
       If you use the --databases or --all-databases option to process
       all tables in one or more databases, an invocation of mysqlcheck
       might take a long time. (This is also true for mysql_upgrade
       because that program invokes mysqlcheck to check all tables and
       repair them if necessary.)

       mysqlcheck is similar in function to myisamchk, but works
       differently. The main operational difference is that mysqlcheck
       must be used when the mysqld server is running, whereas myisamchk
       should be used when it is not. The benefit of using mysqlcheck is
       that you do not have to stop the server to perform table

       mysqlcheck uses the SQL statements CHECK TABLE, REPAIR TABLE,
       ANALYZE TABLE, and OPTIMIZE TABLE in a convenient way for the
       user. It determines which statements to use for the operation you
       want to perform, and then sends the statements to the server to
       be executed.

       The MyISAM storage engine supports all four maintenance
       operations, so mysqlcheck can be used to perform any of them on
       MyISAM tables. Other storage engines do not necessarily support
       all operations. In such cases, an error message is displayed. For
       example, if test.t is a MEMORY table, an attempt to check it
       produces this result:

           shell> mysqlcheck test t
           note     : The storage engine for the table doesn´t support check

       If mysqlcheck is unable to repair a table, see the MariaDB
       Knowledge Base for manual table repair strategies. This will be
       the case, for example, for InnoDB tables, which can be checked
       with CHECK TABLE, but not repaired with REPAIR TABLE.

       The use of mysqlcheck with partitioned tables is not supported.


           It is best to make a backup of a table before performing a
           table repair operation; under some circumstances the
           operation might cause data loss. Possible causes include but
           are not limited to file system errors.

       There are three general ways to invoke mysqlcheck:

           shell> mysqlcheck [options] db_name [tbl_name ...]
           shell> mysqlcheck [options] --databases db_name ...
           shell> mysqlcheck [options] --all-databases

       If you do not name any tables following db_name or if you use the
       --databases or --all-databases option, entire databases are

       mysqlcheck has a special feature compared to other client
       programs. The default behavior of checking tables (--check) can
       be changed by renaming the binary. If you want to have a tool
       that repairs tables by default, you should just make a copy of
       mysqlcheck named mysqlrepair, or make a symbolic link to
       mysqlcheck named mysqlrepair. If you invoke mysqlrepair, it
       repairs tables.

       The following names can be used to change mysqlcheck default
       │ mysqlrepair   │ The default option is │
       │               │ --repair              │
       │ mysqlanalyze  │ The default option is │
       │               │ --analyze             │
       │ mysqloptimize │ The default option is │
       │               │ --optimize            │

       mysqlcheck supports the following options, which can be specified
       on the command line or in the [mysqlcheck] and [client] option
       file groups.  The -c, -r, -a and -o options are exclusive to each

       •   --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.

       •   --auto-repair

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

       •   --character-sets-dir=path

           The directory where character sets are installed.

       •   --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 automatically enables the --fix-db-names
           and --fix-table-names options.

       •   --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
           ´d:t:o,file_name´. The default is ´d:t:o´.

       •   --debug-check

           Print some debugging information when the program exits.

       •   --debug-info

           Print debugging information and memory and CPU usage
           statistics when the program exits.

       •   --default-auth=name

           Default authentication client-side plugin to use.

       •   --default-character-set=charset_name

           Use charset_name as the default character set.

       •   --defaults-extra-file=filename

           Set filename as the file to read default options from after
           the global defaults files has been read.  Must be given as
           first option.

       •   --defaults-file=filename

           Set filename as the file to read default options from,
           override global defaults files.  Must be given as first

       •   --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 will force
           using the old, slow, repair with keycache method, instead of
           the much faster repair by sorting.

       •   --fast, -F

           Check only tables that have not been closed properly.

       •   --fix-db-names

           Convert database names to the format used since MySQL 5.1.
           Only database names that contain special characters are

       •   --fix-table-names

           Convert table names (including views) to the format used
           since MySQL 5.1. Only table names that contain special
           characters are affected.

       •   --flush,

           Flush each table after check. This is useful if you don't
           want to have the checked tables take up space in the caches
           after the check.

       •   --force, -f

           Continue even if an SQL error occurs.

       •   --host=host_name, -h host_name

           Connect to the MariaDB 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.

       •   --no-defaults

           Do not read default options from any option file. This must
           be given as the first argument.

       •   --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,
           mysqlcheck prompts for one.

           Specifying a password on the command line should be
           considered insecure. You can use an option file to avoid
           giving the password on the command line.

       •   --persistent, -Z

           Used with ANALYZE TABLE to append the option PERSISENT FOR

       •   --pipe, -W

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

       •   --plugin-dir=name

            Directory for client-side plugins.

       •   --port=port_num, -P port_num

           The TCP/IP port number to use for the connection.  Forces
           --protocol=tcp when specified on the command line without
           other connection properties.

       •   --print-defaults

           Print the program argument list and exit.  This must be given
           as the first argument.

       •   --process-tables

           Perform the requested operation on tables. Defaults to on;
           use --skip-process-tables to disable.

       •   --process-views=val

           Perform the requested operation (only CHECK VIEW or REPAIR
           VIEW). Possible values are NO, YES (correct the checksum, if
           necessary, add the mariadb-version field), UPGRADE_FROM_MYSQL
           (same as YES and toggle the algorithm MERGE<->TEMPTABLE.

       •   --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

       •   --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

       •   --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.

       •   --skip-database=db_name

           Don't process the database (case-sensitive) specified as

       •   --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.  Forces
           --protocol=socket when specified on the command line without
           other connection properties; on Windows, forces

       •   --ssl

           Enable SSL for connection (automatically enabled with other
           flags). Disable with --skip-ssl.

       •   --ssl-ca=name

           CA file in PEM format (check OpenSSL docs, implies --ssl).

       •   --ssl-capath=name

           CA directory (check OpenSSL docs, implies --ssl).

       •   --ssl-cert=name

           X509 cert in PEM format (check OpenSSL docs, implies --ssl).

       •   --ssl-cipher=name

           SSL cipher to use (check OpenSSL docs, implies --ssl).

       •   --ssl-key=name

           X509 key in PEM format (check OpenSSL docs, implies --ssl).

       •   --ssl-crl=name

           Certificate revocation list (check OpenSSL docs, implies

       •   --ssl-crlpath=name

           Certificate revocation list path (check OpenSSL docs, implies

       •   --ssl-verify-server-cert

           Verify server's "Common Name" in its cert against hostname
           used when connecting. This option is disabled by default.

       •   --tables

           Override 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 MariaDB user name to use when connecting to the server.

       •   --verbose, -v

           Verbose mode. Print information about the various stages of
           program operation.  Using one --verbose option will give you
           more information about what mysqlcheck is doing.

           Using two --verbose options will also give you connection

           Using it 3 times will print out all CHECK, RENAME and ALTER
           TABLE during the check phase.

       •   --version, -V

           Display version information and exit.

       •   --write-binlog

           This option is enabled by default, so that ANALYZE TABLE,
           OPTIMIZE TABLE, and REPAIR TABLE statements generated by
           mysqlcheck are written to the binary log. Use
           --skip-write-binlog to cause NO_WRITE_TO_BINLOG to be added
           to the statements so that they are not logged. Use the
           --skip-write-binlog when these statements should not be sent
           to replication slaves or run when using the binary logs for
           recovery from backup.

COPYRIGHT         top

       Copyright 2007-2008 MySQL AB, 2008-2010 Sun Microsystems, Inc.,
       2010-2020 MariaDB Foundation

       This documentation is free software; you can redistribute it
       and/or modify it only under the terms of the GNU General Public
       License as published by the Free Software Foundation; version 2
       of the License.

       This documentation is distributed in the hope that it will be
       useful, but WITHOUT ANY WARRANTY; without even the implied
       See the GNU General Public License for more details.

       You should have received a copy of the GNU General Public License
       along with the program; if not, write to the Free Software
       Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
       02110-1335 USA or see

SEE ALSO         top

       For more information, please refer to the MariaDB Knowledge Base,
       available online at

AUTHOR         top

       MariaDB Foundation (

COLOPHON         top

       This page is part of the MariaDB (MariaDB database server)
       project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual
       page, see ⟨⟩.
       This page was obtained from the project's upstream Git repository
       ⟨⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2023-05-11.)  If you discover any rendering
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       (which is not part of the original manual page), send a mail to

MariaDB 10.8                   15 May 2020              MARIADB-CHECK(1)