Microsoft has released a significant update for its widely used SQL Server database software.

The company on Monday announced the general availability of SQL Server 2005 Service Pack 2, which contains a number of key enhancements to the software, including full Windows Vista and Office 2007 compatibility.

At the same time, Microsoft also has eased its licensing policy for SQL Server 2005. Owners of the Enterprise Edition are now allowed to run unlimited, virtual instances of the software on a single server. The policy is similar to Microsoft's virtualization rules for running its software on competing platforms, such as the Apple Macintosh. Microsoft requires Vista users wanting to run the operating system in virtual mode on Macs to own a premium edition of Vista.

Service Pack 2 for SQL Server 2005 also includes add-ins that allow Office 2007 users to perform data mining in SQL Server directly within its Excel 2007 or Visio 2007 applications. And new SQL Server Reporting services are now directly compatible with Microsoft's SharePoint content management and collaboration software, allowing direct access to SQL Server reports from within SharePoint.

The service pack also adds support for Oracle databases in the SQL Server Report Builder feature and support for Hyperion's Essbase business intelligence software. Service Pack 2 for SQL Server 2005 is available as a free download from Microsoft's Web site.