After months of criticism that the test build of its cloud-based SQL Data Services (SDS) lacked the horsepower for enterprise-grade applications, Microsoft is scrapping the effort and moving to a pure relational model instead. Microsoft made the surprise move just one week before its annual MIX09 conference in Las Vegas last month. Ironically, The company announced its cloud-based database offering at MIX08, one year before. The test version of SDS that critics panned was based on REST and SOAP Web services interfaces.