There are numerous good reasons to choose Oracle over its competitors in the RDBMS market. These include, in no particular order:
Oracle has the best support for Java and has had that support for the longest time—though other vendors, particularly IBM and Sybase, are moving quickly to catch up.
With regard to the market share, Oracle is the market leader. However, as of 2002, IBM is not far behind. Although Oracle is far and away the leader on Unix, IBM makes up the difference to a large extent in the mainframe market.
Of the top three databases—IBM DB2 and Microsoft SQL Server being the other two—Oracle is the most platform-independent.
These are good reasons for choosing Oracle over its competitors. But to an extent, it doesn't ...