15.2.3 MyISAM Table Storage Formats
MyISAM supports three different storage formats. Two of them, fixed and dynamic format, are chosen automatically depending on the type of columns you are using. The third, compressed format, can be created only with the myisampack utility (see Section 4.6.5, “myisampack — Generate Compressed, Read-Only MyISAM Tables”).
See Section 13.1.18, “CREATE TABLE Statement”, for information about
You can decompress (unpack) compressed
MyISAM tables using myisamchk
--unpack; see Section 4.6.3, “myisamchk — MyISAM Table-Maintenance Utility”, for more information.