5.6. RLS enhancements

What follows is a list of RLS enhancements. The majority of them are introduced in z/OS DFSMS 1.3. Refer to “VSAM functions by release level” on page 2.

5.6.1. RLS/KSDS extended addressability

When VSAM RLS support was announced with DFSMS/MVS V1R3, it did not support VSAM KSDS extended addressability (EA) format. In other words VSAM RLS component retained the 4 GB architectural limit for the component size imposed by using the 4-byte field for the relative byte address (RBA) addressing mechanism. DFSMS/MVS V1R4 removed this restriction by supporting RLS EA for VSAM KSDSs, and therefore VSAM RLS now supports VSAM KSDSs up to the current multivolume limit of 59 DASD volumes.

As in VSAM non-RLS extended addressability, a ...

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