man pages section 1: User Commands

Exit Print View

Updated: July 2014
 
 

mysqlcheck (1)

Name

mysqlcheck - a table maintenance program

Synopsis

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

Description




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 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 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".

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

     If mysqlcheck is unable to repair a table, see
     Section 2.12.4, "Rebuilding or Repairing Tables or Indexes"



MySQL 5.5            Last change: 03/22/2013                    1






MySQL Database System                               MYSQLCHECK(1)



     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.  mysqlcheck also supports
     the options for processing option files described at
     Section 4.2.3.4, "Command-Line Options that Affect Option-
     File Handling".

     o   --help, -?



MySQL 5.5            Last change: 03/22/2013                    2






MySQL Database System                               MYSQLCHECK(1)



         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.

     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, this
         option can be used to select which interface is employed
         when connecting to the MySQL server.

         This option is supported only in the version of
         mysqlcheck that is supplied with MySQL Cluster. It is
         not available in standard MySQL Server 5.5 releases.

     o   --character-sets-dir=path

         The directory where character sets are installed. See
         Section 10.5, "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



MySQL 5.5            Last change: 03/22/2013                    3






MySQL Database System                               MYSQLCHECK(1)



         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 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 10.5, "Character Set Configuration".

     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

         The client-side authentication plugin to use. See
         Section 6.3.6, "Pluggable Authentication".

         This option was added in MySQL 5.5.10.




MySQL 5.5            Last change: 03/22/2013                    4






MySQL Database System                               MYSQLCHECK(1)



     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.

     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.

     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   --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   --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.




MySQL 5.5            Last change: 03/22/2013                    5






MySQL Database System                               MYSQLCHECK(1)



     o   --plugin-dir=path

         The directory in which to look for plugins. It may be
         necessary to specify this option if the --default-auth
         option is used to specify an authentication plugin but
         mysqlcheck does not find it. See Section 6.3.6,
         "Pluggable Authentication".

         This option was added in MySQL 5.5.10.

     o   --port=port_num, -P port_num

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

     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   --silent, -s

         Silent mode. Print only error messages.

     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 6.3.8.4, "SSL Command



MySQL 5.5            Last change: 03/22/2013                    6






MySQL Database System                               MYSQLCHECK(1)



         Options".

     o   --tables

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

     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, 2013, Oracle and/or its affiliates. All
     rights reserved.

     This software and related documentation are provided under a
     license agreement containing restrictions on use and
     disclosure and are protected by intellectual property laws.
     Except as expressly permitted in your license agreement or
     allowed by law, you may not use, copy, reproduce, translate,
     broadcast, modify, license, transmit, distribute, exhibit,
     perform, publish, or display any part, in any form, or by
     any means. Reverse engineering, disassembly, or
     decompilation of this software, unless required by law for



MySQL 5.5            Last change: 03/22/2013                    7






MySQL Database System                               MYSQLCHECK(1)



     interoperability, is prohibited.

     The information contained herein is subject to change
     without notice and is not warranted to be error-free. If you
     find any errors, please report them to us in writing.

     If this software or related documentation is delivered to
     the U.S. Government or anyone licensing it on behalf of the
     U.S. Government, the following notice is applicable:

     U.S. GOVERNMENT RIGHTS Programs, software, databases, and
     related documentation and technical data delivered to U.S.
     Government customers are "commercial computer software" or
     "commercial technical data" pursuant to the applicable
     Federal Acquisition Regulation and agency-specific
     supplemental regulations. As such, the use, duplication,
     disclosure, modification, and adaptation shall be subject to
     the restrictions and license terms set forth in the
     applicable Government contract, and, to the extent
     applicable by the terms of the Government contract, the
     additional rights set forth in FAR 52.227-19, Commercial
     Computer Software License (December 2007). Oracle USA, Inc.,
     500 Oracle Parkway, Redwood City, CA 94065.

     This software is developed for general use in a variety of
     information management applications. It is not developed or
     intended for use in any inherently dangerous applications,
     including applications which may create a risk of personal
     injury. If you use this software in dangerous applications,
     then you shall be responsible to take all appropriate fail-
     safe, backup, redundancy, and other measures to ensure the
     safe use of this software. Oracle Corporation and its
     affiliates disclaim any liability for any damages caused by
     use of this software in dangerous applications.

     Oracle is a registered trademark of Oracle Corporation
     and/or its affiliates. MySQL is a trademark of Oracle
     Corporation and/or its affiliates, and shall not be used
     without Oracle's express written authorization. Other names
     may be trademarks of their respective owners.

     This software and documentation may provide access to or
     information on content, products, and services from third
     parties. Oracle Corporation and its affiliates are not
     responsible for and expressly disclaim all warranties of any
     kind with respect to third-party content, products, and
     services. Oracle Corporation and its affiliates will not be
     responsible for any loss, costs, or damages incurred due to
     your access to or use of third-party content, products, or
     services.





MySQL 5.5            Last change: 03/22/2013                    8






MySQL Database System                               MYSQLCHECK(1)



     This document in any form, software or printed matter,
     contains proprietary information that is the exclusive
     property of Oracle. Your access to and use of this material
     is subject to the terms and conditions of your Oracle
     Software License and Service Agreement, which has been
     executed and with which you agree to comply. This document
     and information contained herein may not be disclosed,
     copied, reproduced, or distributed to anyone outside Oracle
     without prior written consent of Oracle or as specifically
     provided below. This document is not part of your license
     agreement nor can it be incorporated into any contractual
     agreement with Oracle or its subsidiaries or affiliates.

     This documentation is NOT distributed under a GPL license.
     Use of this documentation is subject to the following terms:

     You may create a printed copy of this documentation solely
     for your own personal use. Conversion to other formats is
     allowed as long as the actual content is not altered or
     edited in any way. You shall not publish or distribute this
     documentation in any form or on any media, except if you
     distribute the documentation in a manner similar to how
     Oracle disseminates it (that is, electronically for download
     on a Web site with the software) or on a CD-ROM or similar
     medium, provided however that the documentation is
     disseminated together with the software on the same medium.
     Any other use, such as any dissemination of printed copies
     or use of this documentation, in whole or in part, in
     another publication, requires the prior written consent from
     an authorized representative of Oracle. Oracle and/or its
     affiliates reserve any and all rights to this documentation
     not expressly granted above.

     For more information on the terms of this license, or for
     details on how the MySQL documentation is built and
     produced, please visit blue]MySQL Contact & Questions].

     For additional licensing information, including licenses for
     third-party libraries used by MySQL products, see Preface
     and Legal Notices.

     For help with using MySQL, please visit either the
     blue]MySQL Forums] or blue]MySQL Mailing Lists] where you
     can discuss your issues with other MySQL users.

     For additional documentation on MySQL products, including
     translations of the documentation into other languages, and
     downloadable versions in variety of formats, including HTML
     and PDF formats, see the blue]MySQL Documentation Library].






MySQL 5.5            Last change: 03/22/2013                    9






MySQL Database System                               MYSQLCHECK(1)



ATTRIBUTES
     See attributes(5) for descriptions of the following
     attributes:

     +---------------+--------------------------+
     |ATTRIBUTE TYPE |     ATTRIBUTE VALUE      |
     +---------------+--------------------------+
     |Availability   | database/mysql-55/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://java.net/projects/solaris-userland.  The original
     community source was downloaded from
     http://downloads.mysql.com/archives/mysql-5.5/mysql-5.5.31.tar.gz

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


























MySQL 5.5            Last change: 03/22/2013                   10