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 13, 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
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 on command.
The following names can be used to change mysqlcheck
default behavior: mysqlrepairThe default option is
--repairmysqlanalyzeThe default option is
--analyzemysqloptimizeThe default option is --optimize.PP
mysqlcheck supports the following options:
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. See
Section 9.1, "The Character Set Used for Data and
Sorting".
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 was added in MySQL 5.0.19.
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 often 'd:t:o,file_name'.
o --default-character-set=charset_name
Use charset_name as the default character set. See
Section 9.1, "The Character Set Used for Data and
Sorting".
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 --fast, -F
Check only tables that have not been closed properly.
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 --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 --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, you are prompted for one.
Specifying a password on the command line should be
considered insecure. See Section 7.6, "Keeping Your
Password Secure".
o --port=port_num, -P port_num
The TCP/IP port number to use for the connection.
o --protocol={TCP|SOCKET|PIPE|MEMORY}
The connection protocol to use.
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 --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 --tables
Overrides 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 file so that the table can be
repaired even if the header is corrupted.
o --user=user_name, -u user_name
The MySQL username 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.
SEE ALSO
msql2mysql(1), myisamchk(1), myisamlog(1), myisampack(1),
mysql(1), mysql.server(1), mysql_config(1),
mysql_fix_privilege_tables(1), mysql_upgrade(1),
mysql_zap(1), mysqlaccess(1), mysqladmin(1),
mysqlbinlog(1), mysqld(1), mysqld_multi(1),
mysqld_safe(1), mysqldump(1), mysqlhotcopy(1),
mysqlimport(1), mysqlmanager(1), mysqlshow(1), perror(1),
replace(1), safe_mysqld(1)
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
MySQL AB (http://www.mysql.com/). This software comes
with no warranty.
MySQL 5.0 03/04/2006 FBMYSQLCHECKFR(1)
Man(1) output converted with
man2html