DB2 - Problembeschreibung
Problem IC98361 | Status: Geschlossen |
QUERY USING ZIGZAG IN THE ACCESS PLAN MIGHT PRODUCE WRONG RESULTS WHEN IN2JOIN IS IN THE ACCESS PLAN AS WELL. | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / A10 - DB2 | |
Problembeschreibung: | |
Queries logically similar can produce wrong result. The given scenario is one example Expected result from all the queries:- Acct Acct 3 2012 2012 71 2013 2013 20 Example of incorrect results are as follows:- select test.acct, head.acct, count(*) from db2inst1.employee test join db2inst1.salary test1 on test1.rid = test.id where test.acct =test1.acct and test.acct in ( 2013, 2012 ) and test1.code = '102228' group by test.acct,test1.acct Acct Acct 3 2012 2012 71 select test.acct,test1.acct, count(*) from db2inst1.employee test join db2inst1.salary test1 on test1.rid = test.id where test.acct =test1.acct and test.acct in ( 2012, 2013 ) and test1.code = '102228' group by test.acct,test1.acct ; Acct Acct 3 2013 2013 20 Access plans will show zig zag join used with IN2JOIN in bad case. | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * Queries logically similar can produce wrong result. The * * given * * scenario is one example * * Expected result from all the queries:- * * * * Acct Acct 3 * * 2012 2012 71 * * 2013 2013 20 * * * * * * * * Example of incorrect results are as follows:- * * * * select test.acct, head.acct, count(*) * * from db2inst1.employee test * * join db2inst1.salary test1 on test1.rid = test.id * * where test.acct =test1.acct and test.acct in ( 2013, * * 2012 * * ) and test1.code = '102228' * * group by test.acct,test1.acct * * Acct Acct 3 * * 2012 2012 71 * * * * * * * * * * select test.acct,test1.acct, count(*) * * from db2inst1.employee test * * join db2inst1.salary test1 on test1.rid = test.id * * where test.acct =test1.acct and test.acct in ( 2012, * * 2013 * * ) and test1.code = '102228' * * group by test.acct,test1.acct * * ; * * * * Acct Acct 3 * * 2013 2013 20 * * * * Access plans will show zig zag join used with IN2JOIN in bad * * case. * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 Version 10.1 Fix Pack 4 * **************************************************************** | |
Local-Fix: | |
Disable Zig Zag join using :- db2set DB2_REDUCED_OPTIMIZATION="ZZJN OFF" -IM | |
verfügbare FixPacks: | |
DB2 Version 10.1 Fix Pack 4 for Linux, UNIX, and Windows | |
Lösung | |
First fixed in Version 10.1 Fix Pack 4 | |
Workaround | |
Disable Zig Zag join using :- db2set DB2_REDUCED_OPTIMIZATION="ZZJN OFF" -IM | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 17.12.2013 16.06.2014 02.09.2016 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
Problem behoben lt. FixList in der Version | |
10.1.0.4 |