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. ["Storage" or "Sequential"?]
Last updated: 2002-07-26
Virtual Storage Extendedpartitions rather than address spaces, and uses POWER for input/output rather than JES, but is largely similar to MVS. Subsequent VSE/ESA releases gave VSE the XA-370 channel architecture, 31-bit virtual and real storage support, and data spaces. VSE is the IBM operating system on one-third of installed IBM 4381s and a significant proportion of IBM 9370s as well. It offers transaction processing and batch processing capabilities well beyond Virtual Machine's current capabilities, and has a close affinity with MVS.
Last updated: 1997-06-09