VSAM - Virtual Storage Access Method in z/OS mainframe System

VSAM is a Data Management System, it is a high performance Access Method. VSAM acts as an interface between processing programs and the operating system.

Access Method

Access Methods are ways to maximize the efficiency of data storage and retrieval.

Access Method Types

1) Queued Sequential Access Method : QSAM
2) Basic Sequential Access Method : BSAM
3) Index Sequential Access Method : ISAM
4) Basic Direct Access Method : BDAM
5) Partitioned Data set / Extended : PDS/E

PDS/E - Released the unused space automatically.