Trade-show keynote speeches are a sure soapbox for vendors to dis their competitors. But not since the days of OS/2 versus Windows have barbs been flying as they have recently in the database space. In fact, Microsoft has called in its lawyers over Oracle's recent criticisms of Microsoft's SQL Server performance, Oracle chief executive Larry Ellison mentioned casually during a Wednesday night keynote address at Internet World. "Microsoft's lawyers sent us a letter threatening to sue us," Ellison told the trade-show audience. He said Microsoft was unhappy with his latest stump speech, in which Ellison said that the only software that runs well on SQL Server running clustered Windows 2000 servers is the Transaction Processing Council's TPC-C benchmark suite. The TPC-C is an industry-standard test that measures transaction-processing-system throughput in terms of orders processed per minute. But the letter didn't stop Ellison from reiterating that claim, which he first made publicly at the Oracle OpenWorld trade show in early October. And Oracle officials said they planned to show the same demonstration at Fall Comdex 2000. In a speech at OpenWorld, Ellison offered $10m to anyone who could get any application to run on Microsoft's TPC-C clustered-database configuration that the Transaction Processing Council awarded its top TPC-C price/performance ranking. Microsoft confirmed that its legal department had, indeed, warned Ellison to back off. "When Larry [Ellison] used a copy of SQL Server to run a TPC benchmark scenario and misrepresented SQL Server's capabilities on stage at OpenWorld, he violated Microsoft's licensing agreement," said SQL Server group product manager Steve Murchie. "Our licensing agreement stipulates that no benchmarking can be published without permission -- not unusual. Oracle has the same licensing terms," Murchie added. "In an ongoing attempt to keep Larry Ellison honest, Microsoft issued Oracle a standard cease-and-desist letter." Murchie also took issue with the heart of Ellison's claims about the instability and poor performance of clustered SQL Server configurations. He added that SQL Server 2000 includes new technology that enables scalability clusters and said Microsoft customers were just beginning to test and run real-world applications on that technology. The recent war of words between Microsoft and Oracle is hardly the first clash between the two in the database space. Earlier this summer, Oracle had a hand in toppling Microsoft from its spot atop the TPC-C heap, according to sources close to the benchmarking process. In the interim months, Microsoft resubmitted its SQL Server 2000/Windows 2000 configuration to the TPC-C and currently reigns as number one in the TPC-C rankings. Oracle 8i running on IBM's AIX flavor of Unix ranks number five. Oracle is expecting to rise in the rankings once its Oracle 9i database and Real Application Cluster add-ons are available. Oracle has said 9i is due to ship in March 2001. Oracle and Microsoft are hardly the only ones slinging database mud. IBM -- which holds the number two spot in the current TPC-C rankings, with its DB2 Universal Database running on Windows 2000 -- has gone on the offensive against its competitors, especially Oracle, in recent months. Big Blue has touted recent Meta Group market reports critical of Oracle's pricing compared to IBM's. IBM also has questioned Oracle's claims that it will support mainframe users with Oracle 8i Release 3 better than IBM can or has with its DB2 UDB. To have your say online click on the TalkBack button and go to the ZDNet News forum. Let the editors know what you think in the Mailroom. And read what others have said.