IFCID 002 - ROWID
This topic shows detailed information about
Record Trace - IFCID 002 - ROWID.
Record trace - IFCID 002 - ROWID
The field labels shown in the following sample layout of
Record Trace - IFCID 002 - ROWID are described in the following section.
ROWID DIRECT ACCESS 0 INDEX USED 0 TABLE SPACE SCAN USED 0
- DIRECT ACCESS
The number of times that direct row access was successful.
Field Name: QXROIMAT
- INDEX USED
The number of times an index was used to find a record.
Field Name: QXROIINX
- TABLE SPACE SCAN USED
The number of times that an attempt to use direct row access reverted to using a table-space scan because DB2 was unable to use a matching index scan.
Background and Tuning Information
Ideally, this value should be 0.
Table-space scans can happen, for example, when a REORG is performed between the read of the ROWID column and the use of the host variable in the WHERE clause of the SQL statement. This causes the RID value in the host variable to be incorrect. DB2 first tries a matching-index scan before using a table-space scan.
To avoid table space scans, you can force the access path of an unsuccessful direct row access to use a matching index scan on the primary-index key by adding PKCOL to the WHERE clause in the SQL statement.
.... WHERE ROWIDCOL=:HVROWID AND PKCOL=:HVPK .....
Field Name: QXROITS