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Updated: Thursday, March 14, 2019
 
 

mysqlcheck (1)

Name

mysqlcheck - a table maintenance program

Synopsis

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

Description

MYSQLCHECK(1)                MySQL Database System               MYSQLCHECK(1)



NAME
       mysqlcheck - a table maintenance program

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

DESCRIPTION
       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 (see Section 13.3.5, "LOCK TABLES and
       UNLOCK TABLES Syntax", for more information about READ and WRITE
       locks). 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 must be used when the mysqld server is running, which means
       that you do not have to stop the server to perform table maintenance.

       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.
       For details about which storage engines each statement works with, see
       the descriptions for those statements in Section 13.7.2, "Table
       Maintenance Statements".

       All storage engines do not necessarily support all four maintenance
       operations. In such cases, an error message is displayed. For example,
       if test.t is an MEMORY table, an attempt to check it produces this
       result:

           shell> mysqlcheck test t
           test.t
           note     : The storage engine for the table doesn't support check

       If mysqlcheck is unable to repair a table, see Section 2.11.3,
       "Rebuilding or Repairing Tables or Indexes" 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.

           Caution
           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 checked.

       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 names shown in the following table can be used to change mysqlcheck
       default behavior.

       +--------------+-----------------------+
       |Command       | Meaning               |
       +--------------+-----------------------+
       |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] groups of an
       option file. For information about option files used by MySQL programs,
       see Section 4.2.6, "Using Option Files".

       o   --help, -?

           Display a help message and exit.

       o   --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, except that the INFORMATION_SCHEMA and performace_schema
           databases are not checked. They can be checked by explicitly naming
           them with the --databases option.

       o   --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.

       o   --analyze, -a

           Analyze the tables.

       o   --auto-repair

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

       o   --bind-address=ip_address

           On a computer having multiple network interfaces, use this option
           to select which interface to use for connecting to the MySQL
           server.

       o   --character-sets-dir=dir_name

           The directory where character sets are installed. See
           Section 10.14, "Character Set Configuration".

       o   --check, -c

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

       o   --check-only-changed, -C

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

       o   --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.

       o   --compress

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

       o   --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 any following names as table names. With this option, it
           treats all name arguments as database names.

       o   --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.

       o   --debug-check

           Print some debugging information when the program exits.

       o   --debug-info

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

       o   --default-character-set=charset_name

           Use charset_name as the default character set. See Section 10.14,
           "Character Set Configuration".

       o   --defaults-extra-file=file_name

           Read this option file after the global option file but (on Unix)
           before the user option file. If the file does not exist or is
           otherwise inaccessible, an error occurs.  file_name is interpreted
           relative to the current directory if given as a relative path name
           rather than a full path name.

       o   --defaults-file=file_name

           Use only the given option file. If the file does not exist or is
           otherwise inaccessible, an error occurs.  file_name is interpreted
           relative to the current directory if given as a relative path name
           rather than a full path name.

           Exception: Even with --defaults-file, client programs read
           .mylogin.cnf.

       o   --defaults-group-suffix=str

           Read not only the usual option groups, but also groups with the
           usual names and a suffix of str. For example, mysqlcheck normally
           reads the [client] and [mysqlcheck] groups. If the
           --defaults-group-suffix=_other option is given, mysqlcheck also
           reads the [client_other] and [mysqlcheck_other] groups.

       o   --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!

       o   --default-auth=plugin

           A hint about the client-side authentication plugin to use. See
           Section 6.3.9, "Pluggable Authentication".

       o   --enable-cleartext-plugin

           Enable the mysql_clear_password cleartext authentication plugin.
           (See Section 6.5.1.5, "Client-Side Cleartext Pluggable
           Authentication".)

           This option was added in MySQL 5.7.10.

       o   --fast, -F

           Check only tables that have not been closed properly.

       o   --fix-db-names

           Convert database names to 5.1 format. Only database names that
           contain special characters are affected.

           This option is deprecated in MySQL 5.7.6 and will be removed in a
           future version of MySQL. If it is necessary to convert MySQL 5.0
           database or table names, a workaround is to upgrade a MySQL 5.0
           installation to MySQL 5.1 before upgrading to a more recent
           release.

       o   --fix-table-names

           Convert table names to 5.1 format. Only table names that contain
           special characters are affected. This option also applies to views.

           This option is deprecated in MySQL 5.7.6 and will be removed in a
           future version of MySQL. If it is necessary to convert MySQL 5.0
           database or table names, a workaround is to upgrade a MySQL 5.0
           installation to MySQL 5.1 before upgrading to a more recent
           release.

       o   --force, -f

           Continue even if an SQL error occurs.

       o   --host=host_name, -h host_name

           Connect to the MySQL server on the given host.

       o   --login-path=name

           Read options from the named login path in the .mylogin.cnf login
           path file. A "login path" is an option group containing options
           that specify which MySQL server to connect to and which account to
           authenticate as. To create or modify a login path file, use the
           mysql_config_editor utility. See mysql_config_editor(1).

       o   --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.

       o   --no-defaults

           Do not read any option files. If program startup fails due to
           reading unknown options from an option file, --no-defaults can be
           used to prevent them from being read.

           The exception is that the .mylogin.cnf file, if it exists, is read
           in all cases. This permits passwords to be specified in a safer way
           than on the command line even when --no-defaults is used.
           (.mylogin.cnf is created by the mysql_config_editor utility. See
           mysql_config_editor(1).)

       o   --optimize, -o

           Optimize the tables.

       o   --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. See Section 6.1.2.1, "End-User Guidelines for Password
           Security". You can use an option file to avoid giving the password
           on the command line.

       o   --pipe, -W

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

       o   --plugin-dir=dir_name

           The directory in which to look for plugins. Specify this option if
           the --default-auth option is used to specify an authentication
           plugin but mysqlcheck does not find it. See Section 6.3.9,
           "Pluggable Authentication".

       o   --port=port_num, -P port_num

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

       o   --print-defaults

           Print the program name and all options that it gets from option
           files.

       o   --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
           permissible values, see Section 4.2.2, "Connecting to the MySQL
           Server".

       o   --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.

       o   --repair, -r

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

       o   --secure-auth

           Do not send passwords to the server in old (pre-4.1) format. This
           prevents connections except for servers that use the newer password
           format. This option was added in MySQL 5.7.4.

           As of MySQL 5.7.5, this option is deprecated and will be removed in
           a future MySQL release. It is always enabled and attempting to
           disable it (--skip-secure-auth, --secure-auth=0) produces an error.
           Before MySQL 5.7.5, this option is enabled by default but can be
           disabled.

               Note
               Passwords that use the pre-4.1 hashing method are less secure
               than passwords that use the native password hashing method and
               should be avoided. Pre-4.1 passwords are deprecated and support
               for them was removed in MySQL 5.7.5. For account upgrade
               instructions, see Section 6.5.1.3, "Migrating Away from Pre-4.1
               Password Hashing and the mysql_old_password Plugin".

       o   --shared-memory-base-name=name

           On Windows, the shared-memory name to use, for connections made
           using 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.

       o   --silent, -s

           Silent mode. Print only error messages.

       o   --skip-database=db_name

           Do not include the named database (case-sensitive) in the
           operations performed by mysqlcheck.

       o   --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.

       o   --ssl*

           Options that begin with --ssl specify whether to connect to the
           server using SSL and indicate where to find SSL keys and
           certificates. See Section 6.4.2, "Command Options for Encrypted
           Connections".

       o   --tables

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

       o   --tls-version=protocol_list

           The protocols permitted by the client for encrypted connections.
           The value is a comma-separated list containing one or more protocol
           names. The protocols that can be named for this option depend on
           the SSL library used to compile MySQL. For details, see
           Section 6.4.6, "Encrypted Connection Protocols and Ciphers".

           This option was added in MySQL 5.7.10.

       o   --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.

       o   --user=user_name, -u user_name

           The MySQL user name to use when connecting to the server.

       o   --verbose, -v

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

       o   --version, -V

           Display version information and exit.

       o   --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
       Copyright (C) 1997, 2018, Oracle and/or its affiliates. All rights
       reserved.

       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 warranty of
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 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 02110-1301 USA or see
       http://www.gnu.org/licenses/.



ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+--------------------------+
       |ATTRIBUTE TYPE |     ATTRIBUTE VALUE      |
       +---------------+--------------------------+
       |Availability   | database/mysql-57/client |
       +---------------+--------------------------+
       |Stability      | Uncommitted              |
       +---------------+--------------------------+
SEE ALSO
       For more information, please refer to the MySQL Reference Manual, which
       may already be installed locally and which is also available online at
       http://dev.mysql.com/doc/.

AUTHOR
       Oracle Corporation (http://dev.mysql.com/).



NOTES
       This software was built from source available at
       https://github.com/oracle/solaris-userland.  The original community
       source was downloaded from
       https://dev.mysql.com/get/Downloads/MySQL-5.7/mysql-boost-5.7.22.tar.gz

       Further information about this software can be found on the open source
       community website at https://dev.mysql.com/.



MySQL 5.7                         03/03/2018                     MYSQLCHECK(1)