At first, the company will merely make Postgres available for download, but it will be integrated into the next release of Solaris next year, Sun’s head of software John Loiacono said at a press conference.

There have been many areas where we’ve been getting more and more requests from customers looking for low-cost open-source alternatives, Loiacono said.

The company will also provide 24/7 database support for its customers, and will work with the Postgres developer community to see if some features of Solaris can be leveraged better by the software.

However, Sun said it has no intention of diverging from the Postgres community, which is publicly supporting Sun’s participation. This isn’t going to be ‘Sun Postgres’, Loiacono noted.

The timing of the announcement is interesting, coming just two days after the company announced that old ally Oracle Corp has made Solaris the preferred platform for its own commercial database software.

Loiacono said that Oracle had been aware of Sun’s plans when it signed that deal. He was quieter when asked how Oracle had responded.

He added that Sun’s plans for database support do not begin and end with Postgres. Just because we’re using Postgres now, it doesn’t mean that we’re done, he said. You will see other open-source databases integrated into Solaris.

Embedding the database in Solaris 10 is part of a trend to take advantage of the free or low cost developer databases that are flooding the market. Each major vendor has either an open source or free ‘Express’ version, even Microsoft now.

Embedding a database into the OS isn’t new either. IBM S/38, the predecessor of the AS/400, had a built-in relational database as part of a pitch to make the platform easier to use for midsize firms unable to deal with the complexity of mainframes.

Sun’s bundling of Postgres is part of a strategy to bulk up Solaris with lots of value-added goodies that you don’t typically get as part of a Linux support subscription. In so doing, it is borrowing tricks employed by other platform vendors.

For instance, Sun is bundling the Xen virtualization server, the open source community’s answer to VMWare. That’s similar to Microsoft’s strategy of bundling its own virtualization server with Windows Server.

It’s also bundling Solaris containers for Linux, which is similar to IBM’s strategy on the zSeries to provide the bulletproofing of the more established platform for consolidating multiple Linux instances.