The InnoDB storage engine version 1.0.2 introduced an incompatible change to the format of compressed tables. Some compressed tables that were created with an earlier version of the InnoDB storage engine may need to be rebuilt with a bigger KEY_BLOCK_SIZE before they can be used.

If you must keep your existing database when you upgrade to InnoDB storage engine 1.0.2 or newer, you must perform a “slow” shutdown of MySQL running the previous version of the InnoDB storage engine. Following such a shutdown, and using the newer release of the InnoDB storage engine, you must determine which compressed tables need conversion and then follow a procedure to upgrade these tables. Because most users do not have tables where this process is required, this manual does not detail the procedures required. If you have created compressed tables with the InnoDB storage engine prior to release 1.0.2, review the relevant information on the InnoDB website.