The 5.1 release was very slow getting released
- Percona did work on innodb XtraDB plugin
- Google did patches
- Facebook did a patch set
- Monty Program - New company started by the founder of MySQL, Forked Maria
MySQL 5.1 Sun/Oracle version we now consider it stable
Oracle bought MySQL, and it has gone OK so far.
Use the Innodb Plugin is much better performance than the included version.
Join Optimizations, Stored Procedures, General Scalability Improvements
- SemiSync Replication
- Perf Schema
- MRS (multiple Rollback Segments), InnoDB Recovery, Delete Buffer, MDL, Split InnoDB Buffer Pools (based on the number of buffer pools you want), InnoDB as Default