Oracle has released a preview version of MySQL to coincide with this year’s MySQL Conference and Expo.
The Development Milestone Release (DMR) is of MySQL 5.6.5, and according to a blog post from Rob Young, Product Manager for MySQL, the highlights of the new release are self-healing replication clusters and better query optimization and throughput.
Young says that the new version adds global transaction Ids and automated utilities for self-healing replication clusters, admitting that until now, setting up self-healing replication clusters has been
“somewhat of a pain point for MySQL users with most developing custom solutions or looking to costly, complex third-party solutions for these capabilities.”
The global transaction ids are supported by a set of utilities that make use of them to provide manual or automatic failover to the most up to date slave replica in the event of a master failure.
The new version also promises improvements to complex query optimization and throughput. This has been achieved by a number of changes, starting with the inclusion of subqueries in the optimizer path. Application developers can also consolidate multiple queries and result sets into a single unit of work. Range based queries can be optimized, and you can also include queries using Order By clauses in the optimizer.
To download the MySQL 5.6.5 DMR go to the download site and click the Development Releases tab
Alongside the development release, MySQL is showing off some "Early Access" development features via the MySQL Labs. These are things that may or may not make it into future releases, and the current crop includes InnoDB online operations for adding indexes and renaming columns; and direct access to data in InnoDB without the need to use SQL. This has been added using the memcache API, and gives developers the means to have both fast, simple key/value access and complex query support in their applications.
These improvements can be tried out in the download called "mysql-5.6-labs-april-2012" from MySQL Labs. See the InnoDB blog for details.