QMF query performance can be affected if the QMF application plan is bound when Q.OBJECT_DATA has very few entries. Under these circumstances, the index on Q.OBJECT_DATA is not being used by the optimizer. (The optimizer is a DB2 function that determines the best ways to access a row in a table.) Instead, a table space scan is performed, affecting future performance when Q.OBJECT_DATA contains many entries. You need to rebind the plan so that the index is used.
To determine whether the index on Q.OBJECT_DATA is being used, run the following query:
SELECT BCREATOR, BNAME
FROM SYSIBM.SYSPLANDEP
WHERE DNAME='QMF720'
AND BTYPE='I'
This query selects the owner (BCREATOR) and name (BNAME) of any indexes that the QMF application plan is dependent upon. Although QMF720 is the default plan name, use the name used during QMF installation.
If the result does not indicate an entry for Q.OBJECT_OBJDATAX (Q.OBJECT_DATAX, if you are migrated from QMF V2R2), do the following: