Storage Engineの変更

Default Storage Engine

If you use CREATE TABLE without specifying the ENGINE=... option, the server will use the default. The default storage engine is MyISAM. If you want to change the default to say InnoDB, you can use the configuration directive --default-storage-engine=InnoDB.

Something to be aware of is that if you create a table specifying an engine type that is not enabled, MySQL will automatically fall back to the default. From MySQL 4.1, a warning is issued.
Changing Existing Tables

You can change the storage format of an existing table.

ALTER TABLE t1 ENGINE=InnoDB;
ALTER TABLE t2 ENGINE=HEAP;

作り直さなくていいんだね。