|
Problem IC80512
|
Status: Closed |
DB2 OPTIMIZER MIGHT CHOOSE SUB-OPTIMAL INDEX-ORING ACCESS PLAN WHEN ALL RECORDS IN THE TABLE ARE RETURNED. |
| product: |
DB2 FOR LUW / DB2FORLUW / 950 - DB2 |
| Problem description: |
If a query contains only one predicate, an IN predicate, and all
records in the table qualify the predicate, the optimizer might
choose an index-oring access plan as in the following example
query and access plan:
SELECT * FROM FACT WHERE YEAR IN ( 2012, 2013, 2014 );
...
FETCH
/-----+------\
RIDSCN TABLE: SCHEMA1
| FACT
|
+-----------------+-----------------+
SORT SORT SORT
| | |
IXSCAN IXSCAN IXSCAN
| | |
INDEX: SCHEMA1 INDEX: SCHEMA1 INDEX: SCHEMA1
INDEX1 INDEX1 INDEX1
If all possible values in the column YEAR are referenced in the
values list of the IN predicate, then a table-scan access plan
will be a better choice. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* ALL *
****************************************************************
* PROBLEM DESCRIPTION: *
* Please see the Error Description section. *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 version 9.5 Fix Pack 10. *
**************************************************************** |
| Local Fix: |
|
| Solution |
Problem was first fixed in DB2 version 9.5 Fix Pack 10. |
| Workaround |
not known / see Local fix |
| BUG-Tracking |
forerunner : APAR is sysrouted TO one or more of the following: IC80529
follow-up : |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 20.12.2011
13.11.2012
13.11.2012 |
| Problem solved at the following versions (IBM BugInfos) |
9.5.FP10
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.5.0.10
|
 |
