DB2 - Problembeschreibung
Problem IT06951 | Status: Geschlossen |
POSSIBLE WRONG RESULT FROM SQL STATEMENT JOINING 4 OR MORE COLUMN-ORGANIZED TABLES | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 | |
Problembeschreibung: | |
Under rare conditions, a SQL statement involving equality joins between 4 or more column-organized tables, with a subset of at least 3 tables on the same join columns which are also connected through joins to one or more other tables on different join columns, might produce incorrect results. This is best explained using an example, such as the following: select * from t1,t2,t3,t4 where t1.a=t2.a and t1.b=t4.b and t2.c=t4.c and t2.c=t3.c and t1.d=t3.d where t1,t2,t3, and t4 are column-organized tables. The join between t2,t3, and t4 are on the same column, c. The optimizer identifies this relationship and will consider all join orders involving these 3 tables. Furthermore, t2,t3,and t4 are also connected through the join with t1, but on different columns. In this type of scenario, the optimizer will consider alternative join orders that might cause this error. | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * DB2 UDB Version 10.5 * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to Version 10.5 FixPack 7. * **************************************************************** | |
Local-Fix: | |
If you expect you are hitting this issue, you can apply an optimization guideline to request a different join order from the optimizer. | |
Lösung | |
Problem was first fixed in DB2 UDB Version 10.5 FixPack 7. | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 04.02.2015 20.01.2016 27.04.2016 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
Problem behoben lt. FixList in der Version | |
10.5.0.7 |