|
Problem IC65848
|
Status: Closed |
DB2 INSTANCE MAY ABEND DUE TO MEMORY CORRUPTION IN HSJOIN INIT FUNCTION WHILE EXECUTING SQL WITH LARGE HASH TABLE SIZE. |
| product: |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 |
| Problem description: |
DB2 instance may abend due to memory corruption in hsjoin init
function while executing SQL with large hash table size.
The DB2 instance may abend on specific SQL having hash join
operator with extremely big hash table size (overflowed) with
the following stack
0x000000000000E898 ?unknown + 0x0
0x090000000132F684 sqlogmblkEx + 0x0
0x09000000012496AC sqlri_hsjnInit__FP8sqlrr_cbP11sqlri_hsjnol +
0x3E4
0x090000000138A71C sqlrihsjn__FP8sqlrr_cb + 0x24
0x0900000001370FA0 sqlriSectInvoke__FP8sqlrr_cbP12sqlri_opparm -
0x814
0x090000000143E2C4
sqlrr_process_fetch_request__FP14db2UCinterface + 0x13C
0x09000000013A4C64
sqlrr_open__FP14db2UCinterfaceP15db2UCCursorInfo + 0x58C
0x090000000151BD40
sqljs_ddm_opnqry__FP14db2UCinterfaceP13sqljDDMObject + 0x968
0x090000000151B2F4
sqljsParseRdbAccessed__FP13sqljsDrdaAsCbP13sqljDDMObjectP14db2UC
interface + 0x4
0x09000000013B2800
sqljsParse__FP13sqljsDrdaAsCbP14db2UCinterface - 0x124
If similar stack dump is observed and belongs to the DB2 agent
which executes SQL with joins, it is necessary to check
suspicious SQL plan by means of exlain and db2exfmt and if for
example the following HASHTBSZ value is observed in plan
explanation then this APAR might be applicable for you.
4) HSJOIN: (Hash Join)
Cumulative Total Cost: 3.40282e+38
Cumulative CPU Cost: 3.40282e+38
Cumulative I/O Cost: 3.40282e+38
Cumulative Re-Total Cost: 3.40282e+38
Cumulative Re-CPU Cost: 3.40282e+38
Cumulative Re-I/O Cost: 3.40282e+38
Cumulative First Row Cost: 3.40282e+38
Estimated Bufferpool Buffers: 3.40282e+38
Arguments:
---------
BITFLTR : (Hash Join Bit Filter used)
FALSE
EARLYOUT: (Early Out flag)
NONE
HASHCODE: (Hash Code Size)
32 BIT
HASHTBSZ: (Number of hash table entries)
340282346638528859811704183485000000000
JN INPUT: (Join input leg)
OUTER
OUTERJN : (Outer Join type)
LEFT
TEMPSIZE: (Temporary Table Page Size)
4096 |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All *
****************************************************************
* PROBLEM DESCRIPTION: *
* DB2 instance may abend due to memory corruption in *
* hsjoininitfunction while executing SQL with large hash table *
* size.The DB2 instance may abend on specific SQL having hash *
* joinoperator with extremely big hash table size *
* (overflowed)withthe following stack0x000000000000E898 *
* ?unknown + 0x00x090000000132F684 sqlogmblkEx + *
* 0x00x09000000012496ACsqlri_hsjnInit__FP8sqlrr_cbP11sqlri_hsjno
* +0x3E40x090000000138A71C sqlrihsjn__FP8sqlrr_cb + *
* 0x240x0900000001370FA0sqlriSectInvoke__FP8sqlrr_cbP12sqlri_opp
* -0x8140x090000000143E2C4sqlrr_process_fetch_request__FP14db2UC
* + *
* 0x13C0x09000000013A4C64sqlrr_open__FP14db2UCinterfaceP15db2UCC
* + *
* 0x58C0x090000000151BD40sqljs_ddm_opnqry__FP14db2UCinterfaceP13
* + *
* 0x9680x090000000151B2F4sqljsParseRdbAccessed__FP13sqljsDrdaAsC
* + *
* 0x40x09000000013B2800sqljsParse__FP13sqljsDrdaAsCbP14db2UCinte
* - 0x124If similar stack dump is observed and belongs to the *
* DB2agentwhich executes SQL with joins, it is necessary to *
* checksuspicious SQL plan by means of exlain and db2exfmt *
* and ifforexample the following HASHTBSZ value is observed in *
* planexplanation then this APAR might be applicable for *
* you.4) HSJOIN: (Hash Join)Cumulative Total Cost: *
* 3.40282e+38Cumulative CPU Cost: 3.40282e+38Cumulative I/O *
* Cost: 3.40282e+38Cumulative Re-Total Cost: *
* 3.40282e+38Cumulative Re-CPU Cost: 3.40282e+38Cumulative *
* Re-I/O Cost: 3.40282e+38Cumulative First Row Cost: *
* 3.40282e+38Estimated Bufferpool Buffers: *
* 3.40282e+38Arguments:---------BITFLTR : (Hash Join Bit *
* Filter used)FALSEEARLYOUT: (Early Out flag)NONEHASHCODE: *
* (Hash Code Size)32 BITHASHTBSZ: (Number of hash table *
* entries)340282346638528859811704183485000000000JN INPUT: *
* (Join input leg)OUTEROUTERJN : (Outer Join *
* type)LEFTTEMPSIZE: (Temporary Table Page Size)4096 *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 Version 9.7 Fix Pack 2 *
**************************************************************** |
| Local Fix: |
|
| available fix packs: |
DB2 Version 9.7 Fix Pack 2 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 3 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 3a for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 4 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 5 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 7 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 9a for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 8 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows
|
| Solution |
Problem was first fixed in Version 9.7 Fix Pack 2 |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 28.01.2010
30.06.2010
30.06.2010 |
| Problem solved at the following versions (IBM BugInfos) |
9.7.FP2
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.7.0.2
|
 |
