Oracle, meanwhile, said that few of its customers have actually switched to Microsoft.

'Functionality-wise, take any area of SQL Server 2005 and compare it to Oracle 10g, and ours is unquestionably superior, infinitely superior,' said Willie Hardie, vice president of database product marketing at Oracle.

Oracle is also counterattacking Microsoft in the lower-end market dominated by SQL Server. It released a free version of Oracle 10g aimed at students two weeks ago. And Hardie says that 60 percent of customers for its lower-end Standard Edition One version of 10g switched from other databases, many of them from Microsoft.

As for Version 2006 of BizTalk Server, Microsoft's tool to help companies translate data between different applications, its release will be delayed by up to three months, said Steven Martin, director of BizTalk product management. That until could push the release back to the end of next June.

BizTalk has 5,000 users and competes with products such as IBM's WebSphere and offerings from Tibco Software Inc., WebMethods Inc. and Vitria Technology Inc.