1.13. VSAM exploiters

The major applications that exploit VSAM functions are described in this section.

1.13.1. DB2

DB2 uses linear (LDS) VSAM data sets for its table spaces, without implementing Data-in-Virtual. All the control (including buffer pool) is done by DB2. For example, DB2 implements data striping in LDS data sets.

1.13.2. Hierarchical file system (HFS)

HFS is a UNIX® Services data organization with no determined logical records — it is a byte string — made of embedded directories and data. It can be accessed by Posix code (a UNIX standard for operating system interfaces, APIs) running under z/OS or by z/OS applications. In the second case an HFS looks like a VSAM ESDS organization and is accessed in the same way.

Accessing HFS ...

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