VSAM: Access Method Services and Application Programming

If you've been involved in any type of programming activity on an IBM mainframe computer, you've almost certainly worked with files supported by VSAM, the Virtual Storage Access Method. If so, you know that VSAM provides many features and options. For example, when you issue a DEFINE CLUSTER command to create a VSAM file, you can code about 30 different parameters that select various options for the file. And you can code most of those parameters at one, two, or three levels, with varying results. Although many of those parameters have default settings, those defaults are often inappropriate for many applications. As a result, it's crucial that programmers and analysts at all levels have a solid understanding of VSAM's facilites and how they are best used in a variety of situations. Unfortunately, that kind of understanding isn't easy to come by. Sure, it's easy to pick up an IBM manual and look up the syntx of the DEFINE CLUSTER command. But there's more to understand VSAM than knowing the syntax of the various commands. And remember, IBM's reference manuals are just that: reference manuals. So although they present lots of details, they don't help you decide which VSAM features to use in a given situation. This book is designed not only to teach you the basics of VSAM, but to el you evaluate VSAM as you learn, so you can decide for yourself how to use VSAM effectively in a wide variety of situations. So if you want to learn more than just the syntax of a few commands, this is the book for you.