other versions
MYSQLCHECK(1) | MySQL Database System | MYSQLCHECK(1) |
NAME¶
mysqlcheck - a table maintenance programSYNOPSIS¶
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
shell> mysqlcheck [options] db_name [tbl_name ...] shell> mysqlcheck [options] --databases db_name ... shell> mysqlcheck [options] --all-databases
Command | Meaning |
mysqlrepair | The default option is --repair |
mysqlanalyze | The default option is --analyze |
mysqloptimize | The default option is --optimize |
•--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,
except that the INFORMATION_SCHEMA and performace_schema databases are not
dumped. They can be dumped by explicitly naming them with the
--databases option.
•--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, use this option to select
which interface to use for connecting to the MySQL server.
This option is supported beginning with MySQL 5.6.1.
•--character-sets-dir=dir_name
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 any
following names as table names. With this option, it treats all name arguments
as database names.
This option may be used to dump the INFORMATION_SCHEMA and performace_schema
databases, which normally are not dumped even with the --all-databases
option. (Also use the --skip-lock-tables option.)
•--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”.
•--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. file_name is interpreted relative to the current directory if
given as a relative path name rather than a full path name.
•--defaults-file=file_name
Use only the given option file. If the file does not exist or is otherwise
inaccessible, an error occurs. file_name is interpreted relative to the
current directory if given as a relative path name rather than a full path
name.
•--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.
•--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
A hint about the client-side authentication plugin to use. See
Section 6.3.7, “Pluggable Authentication”.
This option was added in MySQL 5.6.2.
•--enable-cleartext-plugin
Enable the mysql_clear_password cleartext authentication plugin. (See
Section 6.4.1.7, “The Cleartext Client-Side Authentication
Plugin”.)
This option was added in MySQL 5.6.28.
•--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.
•--login-path=name
Read options from the named login path in the .mylogin.cnf login path file. A
“login path” is an option group containing options that specify
which MySQL server to connect to and which account to authenticate as. To
create or modify a login path file, use the mysql_config_editor
utility. See mysql_config_editor(1). This option was added in MySQL
5.6.6.
•--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.
•--no-defaults
Do not read any option files. If program startup fails due to reading unknown
options from an option file, --no-defaults can be used to prevent them
from being read.
The exception is that the .mylogin.cnf file, if it exists, is read in all cases.
This permits passwords to be specified in a safer way than on the command line
even when --no-defaults is used. (.mylogin.cnf is created by the
mysql_config_editor utility. See mysql_config_editor(1).)
•--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=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 6.3.7,
“Pluggable Authentication”.
This option was added in MySQL 5.6.2.
•--port=port_num, -P
port_num
The TCP/IP port number to use for the connection.
•--print-defaults
Print the program name and all options that it gets from option files.
•--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.
•--secure-auth
Do not send passwords to the server in old (pre-4.1) format. This prevents
connections except for servers that use the newer password format. This option
is enabled by default; use --skip-secure-auth to disable it. This
option was added in MySQL 5.6.17.
Note
Passwords that use the pre-4.1 hashing method are less secure than passwords
that use the native password hashing method and should be avoided. Pre-4.1
passwords are deprecated and support for them will be removed in a future
MySQL release. For account upgrade instructions, see Section 6.4.1.3,
“Migrating Away from Pre-4.1 Password Hashing and the
mysql_old_password Plugin”.
•--shared-memory-base-name=name
On Windows, the shared-memory name to use, for connections made using shared
memory to a local server. The default value is MYSQL. The shared-memory name
is case sensitive.
The server must be started with the --shared-memory option to enable
shared-memory connections.
•--silent, -s
Silent mode. Print only error messages.
•--skip-database=db_name
Do not include the named database (case sensitive) in the operations performed
by mysqlcheck. This option was added in MySQL 5.6.11.
•--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 6.3.9.5, “Command Options for Secure
Connections”.
•--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, 2016, 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/).03/02/2016 | MySQL 5.6 |