This IDC study presents estimated relational database management systems (RDBMS) software revenue for each of the top 5 vendors in that market, with a brief profile of each vendor. "2007 was a year that saw continued steady growth in the relational database management systems market, with signal improvements on the part of some of the top 5 vendors in this space," says Carl Olofson, research vice president for IDC's Information Management and Data Integration software research program. "All have put an increased emphasis on performance and manageability as well as greater flexibility and utility of such features as standby databases."