Virtual Storage Access Method (database) (VSAM) An IBM disk file storage scheme first used in S/370 and virtual storage. VSAM comprises three access methods: Keyed Sequenced Data Set (KSDS), Relative Record Data Set (RRDS), and Entry Sequenced Data Set (ESDS).
Both IMS/DB and DB2 are implemented on top of VSAM and use its underlying data structures. ["Storage" or "Sequential"?] Last updated: 2002-07-26
