Suggestions for improving the performance of the DB2 DAY065 job step, processing 50-90 million SMF records per day.
MICS Resource Management r14.2
Check the DB2ACRT routine to see if DB2PLAN is being put into any of the DB2ACTx fields. If so, the DSP file can be turned off saving a huge sort and data setup. If DB2PLAN is not in an account field, then it is worth considering.
In addition, it is worth investigating the ACCUMACC option in DB2. This option will reduce the number of 101, subtype 1 package records by about a 10 to 1 ratio, which will significantly reduce the runtime processing for the DPP file. The only issue with ACCUMACC is that since it does a rollup, some of the package detail is lost. So it depends on how or if you do DB2 Package performance analysis from the DPP file.
Information on DB2 ACCUMACC Roll-up Records is found here
In DB2OPS reduce the number of WORK DD’s. Having a lot of WORK DDs causes the job to run slower and consider spanning the work files across multiple volumes. For example, UNIT=(SYSDA,9) which will span the WORK file across 9 volumes.
For those sites using SYNCSORT, in the MICS-distributed SYNCSORT utility parameters found in the //$ORTPARM DD of any MICS JCL PROC member, add the parameters ELAP and VSCORET=64M. Sites that have added these SYNCSORT parms have reported considerable reduction in the elapsed time of the MICS DB2 component. Refer to the appropriate SYNCSORT documentation for more information about these parameters.
If none of the suggestions above are feasible, then the two best options are to implement Incremental Update or create a new DB2 UNIT & split the data.