Why is the Database Analyzer for Db2 Statistics Maintenance execution frequency being ignored

Products

• Database Analyzer for DB2 for z/OS

Issue/Introduction

From the Database Analyzer for Db2 for z/OS (PDA) Main Menu option 3) Statistics Maintenance, then option 1) Automatic Statistics Deletion:

AUTOMATIC STATISTICS DELETION panel details as follows:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Last Execution: yyyy/mm/dd  hh:mm:ss   Last Update: yyyy/mm/dd  hh:mm:ss
    by User ID: userid                 by User ID: userid             
                                                                        
Auto-Statistics Activation ==> Y       (Y)es, (N)o, (U)pdate            
                                                                        
  Subsystem Connection ID  ==> ssid                                     
  Location                 ==> LOCAL                                    
                                                                        
  Execution Frequency      ==> nnn  Days     Next Execution: yyyy/mm/dd
  Purge Stats Older Than   ==> nnn  Days                                
                                                                        
  Save Latest Stats for Each Object ==> N           (Y)es, (N)o         
  - Save Latest Stats Every x Days  ==> 000  Days   (0-999)             
  - Ignore Save Latest option when                  'Y'- performance tip
    processing column statistics    ==> Y           (Y)es, (N)o         
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The "Next Execution" date has passed and nothing has been run to clean up the statistics.

Resolution

PDA does not automatically start a job on the next execution date. Each time an extract is run, PDA checks the statistics maintenance fields to see
if statistics maintenance has been activated ("Y" in Auto-Statistics Activation). If so, it then checks the next execution date to see if it is due.

If it is due, the auto stats maintenance is triggered during that PDA Extract processing. Subsequent extracts on the same day will not trigger the Statistics Maintenance,
this should only occur once that day (then the next execution date is reset based on options chosen).

Please note:
The Statistics Maintenance will not trigger if the PDA Extract has the override - MAINT=N on the exec statement.
|This will cause the statistics maintenance to never run with that Extract.