|
Problem IC81222
|
Status: Closed |
A QUERY WITH OLAP FUNCTION OVER(PARTITION BY ...) MAY HANG IN SQLRI_BUFFER_DISK_WRITE() |
| product: |
DB2 FOR LUW / DB2FORLUW / 910 - DB2 |
| Problem description: |
A query with OLAP function OVER(PARTITION BY ...) may encounter
a hang in sqlri_buffer_disk_write() function.
This may happen if there is not enough APPLHEAP available and
the rows have a very high number of the same partition values
(high data skew) .
A typical stack trace obtained would show:
<StackTrace>
-------Frame------ ------Function + Offset------
0x090000000BA5D39C
sqlri_buffer_disk_write__FP16sqlri_buffer_mgrPP14sq
0x090000000BA5D534
sqlri_buffer_disk_write__FP16sqlri_buffer_mgrPP14sq
0x090000000BA5E358
@66@sqlri_buffer_get_new_page__FP16sqlri_buffer_mgr
0x0900000009FFECF0
sqlri_buffer_add__FP16sqlri_buffer_mgrP10sqlri_sqzo
0x090000000AE2DEB4 sqlri_scalag__FP8sqlrr_cb - 0x55C
0x090000000AE3FDC8 sqlriSectInvoke__FP8sqlrr_cbP12sqlri_opparm +
0x94
0x090000000A52B8D8 sqlrr_dss_router__FP8sqlrr_cb + 0x230
0x0900000009C4BC60
sqlrr_subagent_router__FP20sqle_agent_privatecbP10s
0x0900000009D449C8 sqleSubRequestRouter__FP13sqle_agent_cbPUiT2
+ 0x41
0x090000000A3DFF30 sqleProcessSubRequest__FP13sqle_agent_cb +
0x230
0x0900000009F4899C sqleRunAgent__FPcUi + 0x8E8
0x090000000AEEBCDC
sqloCreateEDU__FPFPcUi_vPcUlP13SQLO_EDU_INFOPi + 0x
0x090000000AF563E0 sqloSpawnEDU + 0x230
0x090000000AF55F18
sqleCreateNewAgent__FiP8sqlekrcbP17sqlcc_init_struc
0x090000000AF57570
sqleGetAgentFromPool__FiP17sqlcc_init_structT1P12sq
0x090000000AF58170
sqleGetAgent__FiP17sqlcc_init_structT1P12sqlz_app_h
0x090000000AF69668 sqlccipcconnmgr_child__FPcUi + 0x340
...
In addition you will observere that the db2 agent still uses CPU
cycle. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* ALL *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Problem Description above. *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 Version 9.1 Fix Pack 12. *
**************************************************************** |
| Local Fix: |
|
| Solution |
First fixed in DB2 Version 9.1 Fix Pack 12. |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 06.02.2012
02.08.2012
02.08.2012 |
| Problem solved at the following versions (IBM BugInfos) |
9.1.FP12
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.1.0.12
|
 |
