A good two weeks ago, MySQL 5.1.22 was released. MySQL 5.1 is a new release of MySQL Server, with new features like
- partitioning (likely the top feature in 5.1)
- events ("crontab" triggers in the database)
- row-based replication
- table logs
- some XML functions
and also with major bug fixes, such as the AUTO_INCREMENT table-lock contention in InnoDB (fixed now in 5.1.22), as well as early indications of performance improvements of up to 20 % - 40 % on dual cores in some scenarios.
Jay Pipes has written an overview that compresses all of the pointers to 5.1 into one article, MySQL 5.1 Article Recap. I recommend you read it. I also recommend the manual section What's New in MySQL 5.1.
With 5.1.22, MySQL also changed the maturity state to "RC", Release Candidate. Looking at our own Support Policies, Release Candidate (aka Gamma) release is defined as follows:
Release Candidate binaries, also known as Gamma releases, are believed stable, having passed all of MySQL's internal testing, and with all known fatal runtime bugs fixed. However this release has not been in widespread use long enough to know for sure that all bugs have been identified.
However, we recognise that this particular RC does not fit the definition exactly. We still have some fatal runtime bugs left. We are producing an errata list of these, and expect to have the list ready and published on by 23 Oct 2007. We know that we should have published this list together with the RC itself, and we are now working as fast as we can to fix this.
We know we have thus released our RC too early according to our own standards, and we are doing our best to fix it. We apologise for any inconvenience/miscommunication and are working on improving our internal guidelines to ensure it doesn't happen again.
That said, 5.1.22 is a great release, one that we're proud of, and very likely worthy of your attention!