Do schema changes ("migrations") require a lot of advance scheduling and impact your development and business progress? Is an ALTER TABLE on the critical path in your project planning chart? This common problem comes from the fact that most ALTER operations in MySQL cause the table to be locked and rebuilt, which can be a long and intensive process. Learn how Percona Toolkit's pt-online-schema-change tool makes these issues a thing of the past. With pt-online-schema-change, you can alter huge tables while reads and writes continue without interruption.