IT buyers have spent more on Oracle relational and object-relational databases than on similar software from other suppliers in 2002, according to preliminary figures from IDC.
IDC estimated that IT buyers worldwide spent $12.9bn (£8.1bn) on relational and object-relational databases in 2002.
Oracle took 39.4% of that revenue at $5.1bn, a 5% revenue decrease from last year, its second year-on-year revenue drop in a row.
IBM came in second with 33.6% at $4.3bn, a 9% hike, while Microsoft grabbed 11.1% of the market's revenue at $1.4bn, a 15% increase.
Sybase came in fourth, followed by NCR. These five suppliers collectively generate about 90% of the market's revenue.
Oracle was hurt by postponements in spending by large clients on large database installations, while IBM benefited in part from sales to departments within companies.
Microsoft, with its relatively lower-cost and easier-to-use databases, dominated the segment of small and medium-sized businesses.