DB2 (database) A relational database from IBM.
When running under IBM's MVS (Multiple Virtual Storage) operating system, DB2 is implemented on top of VSAM and uses its underlying data structures. DB2, later called "DB2 Universal DataBase", also runs under windows NT, AIX, Solaris and, most recently, Linux. [Details? Was there a "DB1"?] Last updated: 1999-02-01