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   myisamchk    ( 1 )

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MYISAMCHK CHECK OPTIONS

myisamchk supports the following options for table checking operations:

• --check, -c

Check the table for errors. This is the default operation if you specify no option that selects an operation type explicitly.

• --check-only-changed, -C

Check only tables that have changed since the last check.

• --extend-check, -e

Check the table very thoroughly. This is quite slow if the table has many indexes. This option should only be used in extreme cases. Normally, myisamchk or myisamchk --medium-check should be able to determine whether there are any errors in the table.

If you are using --extend-check and have plenty of memory, setting the key_buffer_size variable to a large value helps the repair operation run faster.

For a description of the output format, see the section called 'MYISAMCHK TABLE INFORMATION'.

• --fast, -F

Check only tables that haven´t been closed properly.

• --force, -f

Do a repair operation automatically if myisamchk finds any errors in the table. The repair type is the same as that specified with the --recover or -r option. States will be updated as with --update-state.

• --information, -i

Print informational statistics about the table that is checked.

• --medium-check, -m

Do a check that is faster than an --extend-check operation. This finds only 99.99% of all errors, which should be good enough in most cases.

• --read-only, -T

Do not mark the table as checked. This is useful if you use myisamchk to check a table that is in use by some other application that does not use locking, such as mysqld when run with external locking disabled.

• --update-state, -U

Store information in the .MYI file to indicate when the table was checked and whether the table crashed. This should be used to get full benefit of the --check-only-changed option, but you shouldn´t use this option if the mysqld server is using the table and you are running it with external locking disabled.