VSAM SMS Compression

Help for IBM's record-oriented filesystem VSAM, ESDS, KSDS, RRDS, LDS and Storage management Subsystems

VSAM SMS Compression

Postby dale » Fri Dec 31, 2010 1:48 am

I'm considering implementing VSAM KSDS compression using SMS. I came across APAR II14507 that indicates that REPRO will copy from a compressed to a compressed KSDS without any decompress / compress occurring. (See message IDC0038I COMPRESSION INTERFACE USED, DATA TRANSFER COMPLETE). However, there are requirements like the same CI size, etc AND, at the end of the REPRO, IDCAMS is unable to provide a record count. The same CI size and no record count seems to indicate that IDCAMS is not going through normal load processing. That causes me to think that it might not be re-distributing freespace. Can anyone confirm whether that is true or not. There's a major lack of information available on this comperssion interface.

Posts: 1
Joined: Fri Dec 31, 2010 1:25 am
Has thanked: 0 time
Been thanked: 0 time

Re: VSAM SMS Compression

Postby Bill Dennis » Mon Jan 03, 2011 10:03 pm

It would seem likely that without decompress/compress processing the individual records are not counted and freespace is not redistributed. This sounds like a physical image copy.

You could ask IBM for more info.

Bill Dennis

Disclaimer: My comments on this forum are my own and do not represent the opinions or suggestions of any other person or business entity.
Bill Dennis
Posts: 278
Joined: Thu May 15, 2008 9:45 pm
Has thanked: 0 time
Been thanked: 0 time

Return to VSAM/SMS


  • Related topics
    Last post