18.2.3 MyISAM Table Storage Formats (original) (raw)

18.2.3 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 themyisampack utility (seeSection 6.6.6, “myisampack — Generate Compressed, Read-Only MyISAM Tables”).

When you use CREATE TABLE orALTER TABLE for a table that has noBLOB orTEXT columns, you can force the table format to FIXED orDYNAMIC with the ROW_FORMAT table option.

See Section 15.1.20, “CREATE TABLE Statement”, for information aboutROW_FORMAT.

You can decompress (unpack) compressed MyISAM tables using myisamchk --unpack; seeSection 6.6.4, “myisamchk — MyISAM Table-Maintenance Utility”, for more information.