Why my Area was extended without getting any x37 failure and no apparent reason.

Document ID : KB000019726
Last Modified Date : 14/02/2018
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Symptom:

Messages in the CA Datacom Multi-user (MUF) output log show that an Area that allowed for dynamic extend was extended during a data load but there were no x37 failure or messages. Messages in the MUF log:

 DB01703I - DYNAMIC EXTEND OF AREA CBX00106 STARTED

 DB01701I - DYNAMIC EXTEND OF AREA CBX00106 ENDED, TRACKS BEFORE 2,490 TRACKS AFTER 2,610

Also, a CXX report of the Area before the load showed statistics the Area with a single Table was only 13% full so there was plenty of room with no apparent reason.

Cause:

Prior MUF failure.

Environment:

z/OS and z/VSE

Resolution:

The dynamic extend occurred because the area free space index was inaccurate. This can occur as a result of a MUF failure since the free space index is maintained in memory and processed by the pipeline. The free space index is located in the IXX and Data buffers. If a MUF fails, both the free space index and the CXX statistics may no longer reflect what is actually in a data area.

If you experience this symptom, you can run DBUTLTY with RETIX KEYNAME=*DATA to repair the free space index and DBUTLTY with KEYNAME=*SETR to update the CXX statistics with a more accurate record count.

Additional Information:

More information can be found in the CA Datacom/DB DBUTILTY Reference Guide 14.0 and above: Paragraph: Chapter 37: RETIX (Reconstruct Index)

https://support.ca.com/cadocs/0/CA%20Datacom%20V15%200%20Public-ENU/Bookshelf_Files/PDF/DatacomDB15--DBUTLTY_Ref_zOS_ENU.pdf