DT656I: No table or index has been referenced by stmt viewed

Products

• Detector for DB2 for z/OS

Issue/Introduction

There is a problem with Detector and Subsystem Analyzer. A program which is running has fetch-select-update-open-close. When selecting the T -View Tables/Indexes option for this update sql there is an error DT656I: No table or index has been referenced by stmt viewed. When checking updates made to the same table from the same program using the Subsystem Analyzer, you cannot see the update SQL query that was seen in the detector.

Environment

z/os DB2 

Cause

working as designed

Resolution

Detector (PDT) and Subsystem Analyzer (PSA) are working as designed.
PSA intercepts Db2 GETPAGE requests.  It collects table and index information based on these GETPAGE requests.  In a synchronized PDT and PSA collection the table and index information is associated with the SQL request (OPEN, FETCH, UPDATE, etc) that resulted in the GETPAGE request.  This allows viewing the SQL activity for a table via PSA displays and Table and Index access from PDT for an SQL statement.

In this case the positioned UPDATE did not perform a GETPAGE request, the FETCH did. This was verified by obtaining a Db2 trace record IFCID 58.  Field QW0058GP is the number of GETPAGEs.  The IFCID 58 for the UPDATE this field contained zero, so no table and index information was collected.  The FETCH will show the table and index information.