IBM has taken a piece of open source database start-up EnterpriseDB, a relatively odd thing for IBM to do considering its DB2 interests – unless, of course, it wants to throw sand in Oracle’s eyes – since EnterpriseDB can replace Oracle for vastly less money – or it wants to have an impact on the PostgreSQL database that underlies EnterpriseDB so it can migrate Postgres users to DB2 – anything else and it probably would have done more than simply take part in EnterpriseDB’s $10 million third round along with existing VCs.

However, unless memory plays us false – or there’s been a lot of going on that nobody knows about – IBM has a very thin track record backing open source companies. It was the financial facilitator behind Novell acquiring SUSE and the only open source company it’s ever bought was Gluecode three years ago to protect its WebSphere flank and that’s it.

EnterpriseDB CEO Andy Astor said IBM sought him out about the investment but the two companies were also in the midst of working on the port of EnterpriseDB Advanced Server 8.2 for Linux to the IBM mainframe and for AIX on its p servers.

IBM characterizes it as an “example of its long-standing commitment to open standards.” Not to mention the fact that the $150 million market for open source enterprise databases is supposed to take off over the next few years, growing at 40%-50% a year.

Or that Sun is now the proud possessor of MySQL, a more famous but lighter weight open source database than EnterpriseDB, which is supposed to be more enterprise-fit than its high-profile rival.

Anyway, with the new infusion EnterpriseDB has now taken in a total of $37.5 million. Its VCs include Charles River Ventures, Fidelity Ventures and Valhalla Partners. The money is earmarked for further Postgres development.

EnterpriseDB is hoping to turn profitable at the end of ’09. It remains to be seen whether it’ll take more money. Since recording its first sale in 2006 it has picked up some 200 paying customers.

Meanwhile, EnterpriseDB has moved its freebie and commercial editions to the same unified code base with the same release schedule, changing their names to be closer to the Postgres brand in the process.

Its freebie code is now called Postgres Plus and the company’s commercial Advanced Server is now Postgres Plus Advanced Server.

Both are based on the latest 8.3 release of the Postgres project and both are available on Windows, Linux and Mac OS X with the commercial version adding higher functionality like Oracle compatibility, dynamic performance tuning and sophisticated management and monitoring.

On the Oracle side it can now do bulk collect and bulk binding, explicit transaction control, definer/invoker rights and multithreaded Oracle replication.

The company has also open sourced its previously closed GridSQL business intelligence and data warehousing solution under the GPLv2 license, bundling the parallel query engine with Postgres Plus – as well as Advanced Server – for added scalability allowing it to handle a nearly unlimited number of users and transactions as well as vast amounts of data.

The widgetry has been send down to SourceForge and can be used with the community PostgreSQL project code. Existing database applications run unchanged on GridSQL and application developers can create new applications as though they were accessing a single database on a single server.

The complexity of distributing a query to all the databases in a grid, gathering and collating the resulting information, and returning a single response is transparently handled by GridSQL.

Postgres Plus also includes distributed memory caching, integrated connection pooling and workload profiling along with a one-click cross-platform installer and “Developer QuickStarts” that are supposed to make it easy to adopt Ruby on Rails, JBoss SEAM and REST architectures.

The QuickStarts are also available for Drupal, MediaWiki, phpBB and phpWiki.

The company is adding paid support for Postgres Plus with subscriptions for its and Advanced Server beginning at $995 per socket a year.