By Justin Silverton
Mysql 5.1 beta has recently been released. It is only a beta (and should not be used in a production environment), but it does show us some of the new features that will appear in future, stable, releases:
ALTER TABLE, and
EXPLAIN ... SELECTstatements. As of MySQL 5.1.6, queries against partitioned tables can take advantage of partition pruning. In some cases, this can result in query execution that is an order of magnitude faster than the same query against a non-partitioned version of the same table.
crontab(also known as a “cron job”) or the Windows Task Scheduler.