Getting into Virtual Storage Access Method: An Introduction and Technical Reference

The Virtual Storage Access Method (VSAM) represents IBM's most widely used data storage facility. Getting Into VSAM is a self-study manual and technical reference source that comprises a comprehensive and practical introduction to VSAM. The author discusses direct access storage devices, the history of the development of VSAM, VSAM's purposes and benefits, the three different VSAM file types and their similarities to other access methods, how space is allocated and how data is formatted. Chapters also cover how VSAM keeps track of data, the structure of an index record, the structure and function of the VSAM catalog and the many commands available through Access Methods Services (AMS) to mold VSAM to your particular requirements. There is also practical advice on recovering from and preparing against disaster, security of data files and passwords and accessing VSAM through COBOL, PL/1 and the Assembly Language.