The two firms have competed fiercely in this market over the past several years and in 1997, Oracle topped IBM to move into the top position.
Overall, Dataquest said that the database market grew 15 percent in 1998 to $7.1 billion despite an anticipated sales slowdown due to corporate investment in Year 2000 projects.
IBM's share of the database market for license revenue in 1998 increased to 32.3 percent, up from 28.9 percent in 1997. Oracle, meanwhile, fell slightly from 29.4 percent of all license revenue.
Excluding mainframe and AS/400 database licenses, Oracle remains the leader, according to Dataquest.
Meanwhile, Dataquest reported that Microsoft grew its market share slightly from 9.9 percent in 1997 to 10.2 percent in 1998; Informix Software's piece of the market dropped from 4.8 percent to 4.4 percent; and Sybase dipped from 4.5 percent to 3.5 percent.
An "other" category included in the report accounted for 20 percent.
The firm predicts the database software market will grow to $10 billion by 2003, and analysts say they expect the market to be driven by Internet-related applications, electronic commerce, content management, and the need to support remote and mobile workers.