|
Problem IT03025
|
Status: Closed |
CRASH DURING GROUP BY PROCESSING AGAINST COLUMNAR TABLE IN FUNCTION GETHASH() |
| product: |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 |
| Problem description: |
When a group by query is run against column organized table and
if all of the following conditions are true then DB2 may crash
with below stack trace.
1. Query runs into low sort heap memory situation
2. Low sort heap leads to spilling empty group by hash table
3. Fetches spilled empty group by hash table for final
aggregation
Stack Trace
--------------
getHash
ibm_cde::query::GroupByControlBlock::mergeSpilledEarlyMergedHTsT
oGHT
ibm_cde::query::GroupByControlBlock::completeGroupbyAggregationP
rocessing
ibm_cde::query::LookupGroupingHashTableEvaluator::processInputsS
ynchronously
ibm_cde::query::Evaluator::evaluate
ibm_cde::query::EvaluationRoutine::evaluate
ibm_cde::query::Scheduler::runThreadTask
ibm_cde::query::cdeEntryPointImpl |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All *
****************************************************************
* PROBLEM DESCRIPTION: *
* See APAR description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to 10.5 FP4 *
**************************************************************** |
| Local Fix: |
Workaround
Increase sortheap so that grouping query has suffificent memory
to run entirely in memory and avoid spilling empty hash tables. |
| available fix packs: |
DB2 Cancun Release 10.5.0.4 (also known as Fix Pack 4) for Linux, UNIX, and Windows
DB2 Version 10.5 Fix Pack 9 for Linux, UNIX, and Windows
|
| Solution |
Fix delivered in 10.5 FP4 |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 08.07.2014
08.09.2014
08.09.2014 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 10.5.0.4
|
 |
