This section describes how to rebuild or repair tables or indexes, which may be necessitated by:

Changes to how MySQL handles data types or character sets. For example, an error in a collation might have been corrected, necessitating a table rebuild to update the indexes for character columns that use the collation.

Required table repairs or upgrades reported by CHECK TABLE, mysqlcheck, or mysql_upgrade.

Methods for rebuilding a table include:

1. Dump and Reload Method
2. ALTER TABLE Method
3. REPAIR TABLE Method

Dump and Reload Method

If you are rebuilding tables because a different version of MySQL will not handle them after a binary (in-place) upgrade or downgrade, you must use the dump-and-reload method. Dump the tables before upgrading or downgrading using your original version of MySQL. Then reload the tables after upgrading or downgrading.