IBM MAINFRAME HELP FORUMS for COBOL, JCL, CICS, DB2, IMS etc...

Sukhmeet Singh · Joined: 28 Dec 2007 Posts: 8 Location: kolkata

Which of the following is/are not supported by COBOL?

RBA addressing, Skip-sequential or replacing existing record.

mmwife · Joined: 30 May 2003 Posts: 1480

RBA addressing and Skip sequential are only supported in CICS. I guess that's what he's getting at.

CICS Guy · Joined: 18 Jul 2007 Posts: 1117 Location: At my desk

The following are all out of the Enterprise COBOL for z/OS Programming Guide
hitler26 wrote: RBA addressing
Use the RELATIVE KEY IS clause to associate each logical record with its relative record number.
Quote: Skip-sequential
With dynamic access, you can switch between reading a specific record directly and reading records sequentially, by using READ NEXT for sequential retrieval and READ for random retrieval (by key).
Quote: replacing existing record
Updating records in a VSAM file

mmwife · Joined: 30 May 2003 Posts: 1480

The 1st source you cited is for a relative RECORD read. CICS allows a relative BYTE address read. It gives the CICS coder the ability to access an ESDS rec randomly.

The 2nd is not the same as a "skip sequential" read. In CICS the RIDFLD of the read stmt allows the the key to be skipped for the next read without changing modes or the read stmt; just move the new key to the RIDFLD before the next exec of the read. They say that a performance improvement results provided the gaps in the skips are reasonably small.