Using the MODIFY ACCUM utility

You use the MODIFY ACCUM utility to manage R+/CHANGE ACCUM table space recovery resources.

Managed resources include any associated index resources that are no longer useful for recovery. This utility is comparable to the Db2 MODIFY RECOVERY utility. The MODIFY ACCUM utility:

Related topic

Deleting-R-CHANGE-ACCUM-recovery-resources

  • Deletes the repository records that represent change accumulation files and log ranges
  • Uncatalogs change accumulation files that are no longer usable and scratches them if they are on DASD

You can delete R+/CHANGE ACCUM recovery resources explicitly or implicitly.

This section describes the options for the MODIFY ACCUM statement.

Important

Running the MODIFY ACCUM utility is an important step for efficient use of R+/CHANGE ACCUM.

MODIFY ACCUM utility execution parameters

You specify the MODIFY ACCUM utility parameters on the EXEC statement. You must specify them in the following order:

  • Db2 subsystem ID (required)
  • Message level parameter (optional)

The following figure shows an example of MODIFY ACCUM JCL.

Important

The output files for the MODIFY ACCUM utility are not dynamically allocated. The JCL must have DD statements for the output files.

//ACAMOD1  EXEC PGM=ACAMOD,PARM='DSNA,MSGLEVEL(0)'
//STEPLIB  DD DISP=SHR,DSN=product.libraries
//         DD DISP=SHR,DSN=DB2.DSNEXIT
//         DD DISP=SHR,DSN=DB2.DSNLOAD
//SYSPRINT DD  SYSOUT=*
//SYSERR   DD  SYSOUT=*
//SYSIN    DD  *
 MODIFY ACCUM TABLESPACE MA100DB.MA100TS DSNUM ALL
 TABLESPACE MA200DB.MA200TS
 TORBA X'DEE7D830'
 MODIFY ACCUM TABLESPACE MA300DB.MA300TS
 DELETE AGE *
 MODIFY ACCUM TABLESPACE MA400DB.MA400TS DSNUM 1
 MODIFY ACCUM TABLESPACE MA500DB.MA500TS
 DELETE DATE 091231
 ANALYZE ONLY
/*

Explicit deletion of recovery resources

You can delete recovery resources explicitly through the online interface or through the MODIFY ACCUM utility by using the TORBA/TOLOGPOINT option or the DELETE option.

You can explicitly delete recovery resources with MODIFY ACCUM at the table space or group level by using TABLESPACE or GROUP options.

If you specify TORBA/TOLOGPOINT or DELETE, MODIFY ACCUM deletes repository records that are older than the point you specify.

Implicit deletion of recovery resources

If you do not specify TORBA/TOLOGPOINT or DELETE with MODIFY ACCUM TABLESPACE, MODIFY ACCUM deletes repository records according to the contents of SYSCOPY. For each table space, data set, or partition specified, MODIFY ACCUM retrieves the oldest point of recovery from SYSCOPY. MODIFY ACCUM deletes repository records representing older log ranges.

Important

Do not run the IBM Db2 MODIFY RECOVERY utility to a date later than any image copies or pack backups that you want to use in a recovery.

The MODIFY ACCUM utility reads the SYSCOPY table for any of the following table space events:

  • Oldest full image copy
  • LOAD REPLACE LOG (YES)
  • LOAD LOG (YES)
  • REORG LOG (YES)

The utility deletes change accumulation recovery resources that predate the oldest of these events.

If no entries are found in SYSCOPY and you did not specify TORBA/TOLOGPOINT or DELETE, MODIFY ACCUM does not delete change accumulation resources.

Warning

The MODIFY ACCUM utility deletes recovery resources for which the Db2 internal OBID is different from the log range row OBID. Those change accumulation files are not available for recovery of dropped table spaces.

 

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