Oracle recently released the latest update to the production version of its open source database in the form of MySQL 5.5.18. The release comes with various fixes, most of which deal with replication issues that were detected.
The highlight of the latest update includes a number of statements marked as unsafe for statement-based replication. According to the H Open website, all of the statements given the distinction of being unsafe supposedly “rely on the result of a select statement where the order cannot be relied upon.” Oracle recommends that any users who engage in statement-based logging should read the accompanying documentation for additional guidance regarding the issues addressed in the update. Beyond the replication issue, Oracle also used MySQL 5.5.18 to fix a problem “where the master could send damaged events to slaves if the disk holding the binary log on the master became full.”
MySQL 5.5.18 also includes fixes to correct ARCHIVE and FEDERATED table crashes, plus any corruption problems that occurred with the OPTIMIZE table when using MyISAM. The unnecessary memory allocation and freeing when opening tables has been removed, and the libedit library bundled with MySQL has been given some improvements as well. Finally, Oracle has now made it possible to employ RPM to replace an installed MySQL version with one from the same release family. This improvement could come in handy when upgrading from the GPL version to the commercial version, for example.