|
Problem IC91686
|
Status: Closed |
QUERY HANG WHEN SELECTING LARGE OBJECT COLUMNS FROM A TABLE FUNCTION ON DPF |
| product: |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 |
| Problem description: |
Given a table function that is defined with the ALLOW PARALLEL
attribute on DPF that has an output column that is a large
object, if a select is run against that table function and the
large object column is included more than once in the select
list, then a logic problem may occur in the lob materialization
process that could lead to an infinite hang.
If a trace is taken during the hang, it would show the following
loop:
13 sqlriglf exit
14 sqlriglf entry [eduid 3086 eduname db2agent]
15 | sqldFetchLFD entry [eduid 3086 eduname db2agent]
16 | sqldFetchLFD data [probe 0]
17 | sqldFetchLFD data [probe 1]
18 | | sqldFixExistingTCB entry [eduid 3086 eduname
db2agent]
19 | | sqldFixExistingTCB exit
20 | | sqldx_lob_read entry [eduid 3086 eduname
db2agent]
21 | | sqldx_lob_read exit
22 | sqldFetchLFD data [probe 1000]
23 | sqldFetchLFD exit
24 sqlriglf exit
25 sqlriglf entry [eduid 3086 eduname db2agent]
If a stack is collected using db2pd tool against the coordinator
agent during the hang, the resulting stack traceback file would
show a codepath like this:
_Z18sqldFixExistingTCBP8sqeAgentP16sqeLocalDatabaseP9SQLP_LSN8ii
iiPP8SQLD_TCB
_Z12sqldFetchLFDP8sqeAgentP9sqllf_lseiiPiPc
_Z8sqlriglfP8sqlrr_cbP9sqllf_lseiPiPh
_Z8sqlrimsoP8sqlrr_cbP9sqllf_csoPhPjjisPPvi
_Z23sqlriWriteCsoIntoBufferP8sqlrr_cbP9sqllf_csolPPvlPhPmPl
_Z34sqljsDrdaAsCBPutLongDataQueryCheckP14db2UCinterfaceP9sqllf_c
soPmllPPv
_Z34sqlriPutLobLongDatalinksQueryCheckP14db2UCinterfacelP10sqlz_
valueP7DDValuelPl
_Z14sqlribnoCbDrdaP14db2UCinterface
_Z8sqlribnoP8sqlrr_cb
_Z15sqlriSectInvokeP8sqlrr_cbP12sqlri_opparm
_Z11sqlrr_fetchP14db2UCinterfaceP15db2UCCursorInfo
_Z16sqljs_ddm_cntqryP14db2UCinterfaceP13sqljDDMObject
_Z21sqljsParseRdbAccessedP13sqljsDrdaAsCbP13sqljDDMObjectP14db2U
Cinterface
_Z10sqljsParseP13sqljsDrdaAsCbP14db2UCinterfaceP8sqeAgentb |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All user running DB2 v970 FP8 and lower *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 v970 FP9 or higher *
**************************************************************** |
| Local Fix: |
|
| available fix packs: |
DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 9a for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows
|
| Solution |
|
| Workaround |
not known / see Local fix |
| BUG-Tracking |
forerunner : APAR is sysrouted TO one or more of the following: IC92732 IC95351
follow-up : |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 19.04.2013
17.12.2013
17.12.2013 |
| Problem solved at the following versions (IBM BugInfos) |
9.7.0
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.7.0.9
|
 |
| 9.7.0.9
|
|
