In the area of database instructional book sales, considered a good indicator of developer interest, sales of SQL Server how-to books have surpassed MySQL books this year, according to Roger Magoulis, director of research at leading publisher, O'Reilly Media Inc. He believes that interest is due more to the general release of SQL Server 2005 last fall, rather than just its free edition -- especially as sales of Oracle or DB2 how-to books have inot ncreased significantly since the release of their free versions.

Sybase says its Adaptive Server Enterprise 15 express edition has been downloaded 45,000 times since its September release, with 'a lot of that converting into business,' according to Marty Beard, Sybase's senior vice president of corporate development and marketing.

Microsoft, which released its first free database, MSDE, back in 1999, did not immediately provide the number of downloads of SQL Server 2005 Express, which was released last October. But Oracle said hundreds of thousands of developers and students have downloaded Oracle XE since its beta release that same month. IBM's DB2 Express-C was made generally available only in late January.

In contrast, the latest 5.0 version of MySQL has been downloaded more than 6 million times since October, said Zack Urlocker, vice president of marketing at the Cupertino, Calif.-based firm. 'Sure, the express versions are free, but they come with very significant limitations, especially the lack of support,' Urlocker said. 'No enterprise customer will go into production with a database that cannot be supported.'

MySQL user Andy Meadows said he hasn't been tempted to switch.