High CPU Times With Cleanup AT8#RPT with PARM='REF=030' or PARM='UNREF=030'

Products

• Cleanup

Issue/Introduction

When running the program AT8#RPT with PARM='REF=030' or PARM='UNREF=030', the result is very high CPU time (46 mins CPU and nearly an hour elapsed).

When the same report is run with PARM='BOTH', it takes just 5 seconds of CPU.

Environment

Release:
Component: ETCLNR

Resolution

The situation is normal:

• When you specify PARM=BOTH, there is, in effect, no major selection criteria.
  
  
• When you specify PARM='REF=030', Cleanup has to create storage for each object that matches the criteria. This requires a large number of GETMAINs depending on the size of databases, etc.

Additional Information

Note: if you use the report to create commands to delete entries and you execute those commands, the next time you run the report there will not be as many entries to be retained in our tables and the report will run much quicker.

Also please note the difference between these applicable SAMPJCL members:

DBRPT: This is the report-only job with no command generation. The GETMAINs will not occur. The job should run with very low overhead. So this type of job could run frequently without any performance problem.

DBRPTC: This report job will generate commands. Generating commands will make the processing expensive. These GETMAINs must be done in order to remember what objects are to be deleted and correlated with the RACF security file. So this type of report should not run frequently.