Provided by: mysql-client-core-5.5_5.5.35+dfsg-1ubuntu1_amd64 bug

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” 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.

       ┌──────────────┬──────────────────────────────────┐
       │CommandMeaning                          │
       ├──────────────┼──────────────────────────────────┤
       │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”.

       ·   --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 checked.

       ·   --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.

       ·   --character-sets-dir=path

           The directory where character sets are installed. See Section 10.5, “Character Set
           Configuration”.

       ·   --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-character-set=charset_name

           Use charset_name as the default character set. See Section 10.5, “Character Set
           Configuration”.

       ·   --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!

       ·   --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.

       ·   --fast, -F

           Check only tables that have not been closed properly.

       ·   --fix-db-names

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

       ·   --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.

       ·   --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, 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.

       ·   --pipe, -W

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

       ·   --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.

       ·   --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 permissible 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 using SSL and
           indicate where to find SSL keys and certificates. See Section 6.3.8.4, “SSL Command
           Options”.

       ·   --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 MySQL user name 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.

       ·   --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 © 1997, 2013, 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/.

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/).