4.4.6.5 Other Options for myisamchk

Other actions that myisamchk can do, besides repair and check tables:

-a or --analyze

Analyse the distribution of keys. This improves join performance by enabling the join optimiser to better choose in which order it should join the tables and which keys it should use: myisamchk --describe --verbose table_name' or using SHOW KEYS in MySQL.

-d or --description

Prints some information about table.

-A or --set-auto-increment[=value]

Force AUTO_INCREMENT to start at this or higher value. If no value is given, then sets the next AUTO_INCREMENT value to the highest used value for the auto key + 1.

-S or --sort-index

Sort the index tree blocks in high-low order. This will optimise seeks and will make table scanning by key faster.

-R or --sort-records=#

Sorts records according to an index. This makes your data much more localised and may speed up ranged SELECT and ORDER BY operations on this index. (It may be very slow to do a sort the first time!) To find out a table's index numbers, use SHOW INDEX, which shows a table's indexes in the same order that myisamchk sees them. Indexes are numbered beginning with 1.

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