DB2 - Problem description
Problem IT19980 | Status: Closed |
DB2 MAY FAIL EXECUTING QUERY DURING SEMIJOIN PROCESSING ON CDE | |
product: | |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 | |
Problem description: | |
During execution of SQL containing JOINs, DB2 may choose SEMIJOIN strategy. The problem happens during join pushdown to CDE columnar engine. DB2 fails during construction of right filtering in case when outer/left side of the join at the top is a nested query. Once this happens, SQL returns SQL0901N error: SQL0901N The SQL statement or command failed because of a database system error. (Reason "unexpected error at Parser.cpp:3723".) SQLSTATE=58004 In the db2diag.log error is logged in ibm_cde::query::Parser::prepareCompositeTree: 2017-02-12-18.14.45.498227-300 I937426A3404 LEVEL: Error PID : 46007304 TID : 189992 PROC : db2sysc 0 INSTANCE: DB2INST1 NODE : 000 DB : SAMPLE APPHDL : 0-45884 APPID: 10.5.108.200.41560.170212231204 AUTHID : DB2INST1 HOSTNAME: node1 EDUID : 189992 EDUNAME: db2agent (SAMPLE) 0 FUNCTION: DB2 UDB, CDE Trace, cdeDiagnosticsFacility, probe:3723 DATA #1 : String, 235 bytes AssertionFailedException: An assertion 'mKeyJoinMap.find(AuxKeyIdPair(AuxKeyIdPair(queryId,refKey))) != mKeyJoinMap.end()' failed. Additional info: query_qref to unknown query qid=7005 kentry=1 in query 8014 Thrown at Parser.cpp : 3723 DATA #2 : Function name in Library, 64 bytes ibm_cde::query::Parser::prepareCompositeTree(SyntaxTree *, bool) DATA #3 : File name, 10 bytes Parser.cpp CALLSTCK: (Static functions may not be resolved correctly, as they are resolved to the nearest symbol) The corresponding stack : 0 pthread_kill 1 sqloDumpEDU 2 sqldDumpContext 3 sqlrr_dump_ffdc 4 sqlzeDumpFFDC 5 sqlzeSqlCode 6 sqlrrSqlCode 7 ibm_cde::services::AssertionFailedException::done 8 ibm_cde::services::AssertionFailedException::constructAndThrow 9 ibm_cde::query::Parser::prepareCompositeTree 10 ibm_cde::query::Parser::parserWrapper 11 ibm_cde::query::Parser::prepareNestedQuery 12 ibm_cde::query::Parser::parserWrapper 13 cdeInterface::initializeData 14 cdeInterface::openTableScan 15 sqlriCdeOpen 16 sqlriCdeQuery 17 sqlriSectInvoke 18 sqlrr_process_fetch_request 19 sqlrr_open 20 sqljsParseRdbAccessed 21 sqljsSqlam 22 sqljsSqlam 23 sqljsSqlam 24 sqljsDriveRequests 25 sqljsDrdaAsInnerDriver 26 sqeAgent::RunEDU 27 sqeAgent::RunEDU 28 sqzEDUObj::EDUDriver 29 sqloEDUEntry | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * CDE * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to Db2 Version 10.5 Fix Pack 10 * **************************************************************** | |
Local Fix: | |
The workaround is to disable SEMIJOIN. It can be accomplished by optimization guidelines for the query: /* */ ; | |
Solution | |
Workaround | |
not known / see Local fix | |
BUG-Tracking | |
forerunner : follow-up : IT22344 | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 31.03.2017 16.07.2018 16.07.2018 |
Problem solved at the following versions (IBM BugInfos) | |
Problem solved according to the fixlist(s) of the following version(s) |