(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"?] (2002-07-26)