DBUTLTY OLREORG with REFGROUP=0 for Disk Backup and Restore tables

Products

• Datacom
• Datacom/DB
• Datacom/AD
• DATACOM - AD
• DISK BACKUP AND RESTORE
• Disk Backup and Restore - MVS

Issue/Introduction

What are the required steps to set up Datacom OLREORG (Online Reorg) with REFGROUP=0 in order to perform a reorganization of the Disk Backup and Restore tables?

Environment

Release : 15.0/15.1

Component : CA Datacom/AD

Resolution

OLREORG with REFGROUP=0 requires DSOP attribute set to 4 or 5. Disk Backup and Restore PTF RO90201 changes the DSOP value from 1 to 4 (RANDOM FOR OLREORG).

Moreover, as this utility makes use of empty blocks, it is necessary that there is enough free space on the area. Usually 30% is enough, but it depends on how badly organized the tables are

The required steps are the following:

1. apply all the Datacom PTFs related to OLREORG
2. check if there is enough free space on the DMS area and on the volumes where it's allocated ; if not, extend the area (see "How to extend a CA Datacom area while the database is open" article)
3. check if the DSOP value is already set to 4 (RANDOM FOR OLREORG): run a DBUTLTY CXX report for the Disk database and search for the "DSOP MODE" string for the DMS area. If the value is not "RANDOM FOR OLREORG", then you can dynamically change it running these additional steps:
   1. run a DBUTLTY CXXMAINT with the following cards:

      //SYSIN DD *
      CXXMAINT OPTION=ALTER,AREA=DMS,DBID=nnn,DSOP=4
      /*

   2. run a DBUTLTY RETIX KEYNAME=*DATA (DATACOM/AD 15.0):

      //SYSIN DD *
      RETIX AREA=DMS,DBID=nnn,KEYNAME=*DATA
      /*

      or a DBUTLTY DATASCAN OPTION=REBUILD_SPACE_INDEX (DATACOM/AD 15.1):

      //SYSIN DD *
      DATASCAN AREA=DMS,DBID=nnn,OPTION=REBUILD_SPACE_INDEX
      /*

   3. the Disk database must be closed and immediately reopened to commit the changes, so execute another DBUTLTY job:

      //SYSIN    DD  *                      
      ACCESS STATUS=OFF,DBID=nnn,USERS=WAIT  
      COMM   OPTION=CLOSE,DBID=nnn
      ACCESS STATUS=WRITE,DBID=nnn        
      /*          

4. At this point, the Disk area is ready for the DBUTLTY OLREORG with REFGROUP=0; run the utility on one table at a time:

   //SYSIN DD *
   OLREORG TABLE=ttt,DBID=nnn,REFGROUP=0
   /*

Additional Information

Important notes:

• the very first OLREORG on a table could take several hours to complete (it could run longer than 24 hours, depending on the number of rows on the table and how badly the data are currently organized); you can cancel the OLREORG job (or REQABORT the related Datacom request) and then resubmit the job later.
• the process will cause a number of SPILL requests during the execution, and they must be run immediately to avoid MUF to stop performing the updates. This is because LXX has to record each and every row that is moved by OLREORG.