In case you, like many people, were mystified by the recent announcement of SQL Server 2005 Compact Edition Release Candidate 1 (RC1), it might help to know that SQL Server 2005 Compact Edition is essentially SQL Server Everywhere Edition renamed. In fact, this SQL Server Compact Edition naming thing gets rather complicated because SQL Server 2000 Windows CE Edition (SQL Server CE), SQL Server 2005 Mobile Edition, SQL Server 2005 Everywhere Edition, and SQL Server 2005 Compact Edition are all essentially the same product. The confusing array of names has made it difficult to keep up with what the product is all about. The last iteration of this product, SQL Server 2005 Everywhere Edition, was the most confusing of all because of its name’s similarity to Sybase’s SQL Anywhere mobile database application. ISVs and other partners understandably found the SQL Server Everywhere and SQL Anywhere names too similar, so Microsoft renamed its lightweight database SQL Server 2005 Compact Edition.

SQL Server 2005 Compact Edition’s true nature is a single-user database application. However, its SQL Server CE and SQL Server 2005 Mobile Edition heritage can lead people to think that the Compact Edition is limited to mobile devices. That’s not the case. The RC1 release can run on mobile devices and the usual Windows platform. It’s also important to understand that the new edition is entirely different from SQL Server 2005 Express Edition. SQL Server 2005 Compact Edition is a single-user database that runs as an application and uses a stripped-down version of the SQL Server database engine as its core. For device compatibility, the product uses a small 5MB memory footprint, and it can support databases up to 4GB. In contrast, the SQL Server 2005 Express Edition is a multi-user database that uses a SQL Server engine database core and runs as a service.

So after all of the name changes, you might wonder whether the SQL Server 2005 Compact Edition is a new edition in name only. But the new name was only one change in the new edition; Microsoft also added a variety of new functions. For example, the platform supports Windows 2000, adding to the Windows Mobile and Windows XP support in the preceding SQL Server 2005 Everywhere Edition. Microsoft also made a number of other minor enhancements to the product, including desktop performance enhancements, Windows Vista support, DataDirectory support for the SqlCeConnection object, integration with Visual Studio, and support for SQL Server Compact Edition in SQL Server Management Studio in the upcoming release of SQL Server 2005 Service Pack 2 (SP2). Like it’s predecessor, SQL Server 2005 Everywhere Edition, the Compact Edition is localized in 20 different languages. Notably, it still doesn’t support stored procedures. SQL Server 2005 Compact Edition is a free download that you can get at http://www.microsoft.com/downloads/details.aspx?FamilyId=85E0C3CE-3FA1-453A-8CE9-AF6CA20946C3&displaylang=en.

SQL Server 2005 Compact Edition should mark the end of the naming merry-go-round for this mobile- and desktop-oriented member of the SQL Server product family. At least we can all hope this is the case. For more information about the SQL Server 2005 Compact Edition, see the product’s home page at http://www.microsoft.com/sql/editions/compact/default.mspx.