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MYSQLCHECK(1)                               MySQL Database System                              MYSQLCHECK(1)



NAME
       mysqlcheck - a table maintenance and repair program

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

DESCRIPTION
       The mysqlcheck client checks, repairs, optimizes, and analyzes tables.

       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 check or repair your tables.

       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 Chapter 12, SQL
       Statement Syntax.

       The MyISAM storage engine supports all four statements, so mysqlcheck can be used to perform all four
       operations 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

       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 [tables]
          shell> mysqlcheck [options] --databases db_name1 [db_name2 db_name3...]
          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 following names can be used to change mysqlcheck default behavior.

       +--------------+----------------------------------+
       |mysqlrepair   | The default option is --repair   |
       +--------------+----------------------------------+
       |mysqlanalyze  | The default option is --analyze  |
       +--------------+----------------------------------+
       |mysqloptimize | The default option is --optimize |
       +--------------+----------------------------------+

       mysqlcheck supports the options in the following list. It also reads option files and supports the
       options for processing them described at Section 4.2.3.2.1, "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.

         --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 'd:t:o,file_name'. The default is
          'd:t:o'.

         --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 5.5.6.2,
          "End-User Guidelines for Password Security".

         --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 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.

COPYRIGHT
       Copyright 2007-2008 MySQL AB, 2009 Sun Microsystems, Inc.

       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
       Sun Microsystems, Inc. (http://www.mysql.com/).



MySQL 5.0                                        05/07/2009                                    MYSQLCHECK(1)