|
Problem IC97774
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Status: Closed |
INSTANCE MIGHT ABEND OR RETURN INCORRECT RESULTS DUE TO AN INCORRECT EXECUTION SECTION FOR STAR JOIN |
| product: |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 |
| Problem description: |
An instance might abend or return incorrect results under some
very specific access plan conditions.
A typical trap file might show the following functions at the
top of the stacktrace report:
sqlriREBAL2
sqldEvalDataPred
sqldReadTemp
sqldfrd
sqldRowFetch
sqlsfetc
sqlriFetch
sqlriNljnNonPiped
sqlrihsjn
sqlriSectInvoke
The problem is due to an incorrect buffer location that is being
accessed. This can only be confirmed by db2 service personnel
by examining the "section dump" of the execution plan. The
"section dump" is located in the binary dump file.
From an access plan point of view, at least the following
conditions must be true:
- There is a star join that has a join of a dimension table
above the IXAND operator that references the same columns of the
dimension table that was already accessed in the star join below
the IXAND operator. This might also be referred to as a back
join.
- The dimension table column that is accessed in the star join
and also later used in the back join is accessed by the Data
Sargable Predicate and the column. The dimension table column
must also not be added to the Output Stream of the Table Scan. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All users *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 version 9.7.0.10. *
**************************************************************** |
| Local Fix: |
There is no known workaround for this problem other than to
force a different access plan to avoid at least one of the above
conditions. |
| Solution |
The problem is first fixed in DB2 version 9.7.0.10. |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 19.11.2013
06.11.2014
06.11.2014 |
| Problem solved at the following versions (IBM BugInfos) |
9.7.0.10
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.7.0.10
|
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