mariadbcheck(1)



MYSQLCHECK(1)               MariaDB 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. 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.

       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 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.

           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 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 following options, which can be specified on
       the command line or in the [mysqlcheck] and [client] option file
       groups.

       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.

       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   --character-sets-dir=path

           The directory where character sets are installed.

       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 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-auth=name

           Default authentication client-side plugin to use.

       o   --default-character-set=charset_name

           Use charset_name as the default character set.

       o   --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.

       o   --defaults-file=filename

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

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

       o   --fast, -F

           Check only tables that have not been closed properly.

       o   --fix-db-names

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

       o   --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.

       o   --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.

       o   --force, -f

           Continue even if an SQL error occurs.

       o   --host=host_name, -h host_name

           Connect to the MariaDB 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   --no-defaults

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

       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. You can use an option file to avoid giving the password
           on the command line.

       o   --persistent, -Z

           Used with ANALYZE TABLE to append the option PERSISENT FOR ALL.

       o   --pipe, -W

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

       o   --plugin-dir=name

            Directory for client-side plugins.

       o   --port=port_num, -P port_num

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

       o   --print-defaults

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

       o   --process-tables

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

       o   --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.

       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.

       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   --skip-database=db_name -s

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

       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

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

       o   --ssl-ca=name

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

       o   --ssl-capath=name

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

       o   --ssl-cert=name

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

       o   --ssl-cipher=name

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

       o   --ssl-key=name

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

       o   --ssl-crl=name

           Certificate revocation list (check OpenSSL docs, implies --ssl).

       o   --ssl-crlpath=name

           Certificate revocation list path (check OpenSSL docs, implies
           --ssl).

       o   --ssl-verify-server-cert

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

       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 MariaDB user name to use when connecting to the server.

       o   --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
           information.

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

       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 2007-2008 MySQL AB, 2008-2010 Sun Microsystems, Inc.,
       2010-2015 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 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 MariaDB Knowledge Base,
       available online at https://mariadb.com/kb/

AUTHOR
       MariaDB Foundation (http://www.mariadb.org/).

MariaDB 10.1                      14/12/2015                     MYSQLCHECK(1)

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