Worldwide relational database management systems (RDBMS) total software revenue totaled $13.8 billion in 2005, an 8.3 percent increase from 2004 revenue, according to Gartner, Inc.

The top 5 vendors accounted for nearly 92 percent of the total RDBMS market. Of the top 5 vendors, Microsoft was the only vendor to experience a growth rate above the industry average, mainly as a result of pent-up demand for SQL Server 2005.

Oracle - $6.7B (48.6% share)
IBM - $3.04B (22.0% share)
Microsoft - 2.07B (15.0% share)
Teradata - 0.44B (3.2% share)
Sybase - 0.41B (2.9% share)
Other Vendors - 1.13B (8.2% share)

Linux grew the fastest of all the RDBMS platforms (84 percent), driven primarily by Oracle, and the maturation and user acceptance of the Linux platform as a mission-critical DBMS platform. RDBMS on the mainframe platform continued to show strength, growing faster than the Unix platform, and even beating the overall growth rate.

Gartner analysts said the worldwide RDBMS market is poised for continued growth through 2010 as data management and integration take on a strategic importance in an increasing number of organizations