mysqlcheck


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 2.11.4,
       "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.

       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
           "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 10.5,
           "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. Before MySQL 5.5.8,

       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 6.3.6, "Pluggable Authentication".

           This option was added in MySQL 5.5.10.

       o   --enable-cleartext-plugin

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

           This option was added in MySQL 5.5.47.

       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   --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 6.3.6,
           "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   --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.

           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   --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 6.4.5, "Command Options for Secure
           Connections".

       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.

       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/).



MySQL 5.5                         11/26/2016                     MYSQLCHECK(1)
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