|(database)||Virtual Storage Access Method - (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.