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 4.6.4, “myisampack — Generate Compressed, Read-Only MyISAM Tables”).
See Section 12.1.5, “CREATE TABLE Syntax”, for information about
You can decompress (unpack) compressed
tables using myisamchk
Section 4.6.2, “myisamchk — MyISAM Table-Maintenance Utility”, for more information.