DB2 - Problem description
Problem IT36682 | Status: Closed |
QUERY WITH INDEX SCAN ON A COLUMNAR TABLE WHICH IS UNDER A UNIONMAY GET INCORRECT RESULT | |
product: | |
DB2 FOR LUW / DB2FORLUW / B50 - DB2 | |
Problem description: | |
QUERY WITH INDEX SCAN ON A COLUMNAR TABLE WHICH IS UNDER A UNION MAY GET INCORRECT RESULT. Union leg with the CDE index fetch needs to be more complex - for example, have NLJN between CDE index scan and Union. Example of the plan: Plan Graph: Rows Operator (ID) Cost 2 RETURN ( 1) 12.0948 | 2 SCAN ( 2) 12.0948 | 2 SORT ( 3) 12.0133 | 2 UNION ( 4) 11.8146 / 1 1 NLJN *SCAN* ( 5) ( 9) 11.8098 0.0048 / | 1 1 TFunc: FETCH *SCAN* SYSIBM ( 6) ( 8) GENROW 2.60333 9.20648 / | 1 1 1 ISCAN Columnar Table: Table: ( 7) Schema ELENA 0.20428 Table_CDE Table_ROW | 1 Index: Schema Index_name | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * BLU * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to 11.5 FP7 or later * **************************************************************** | |
Local Fix: | |
db2set DB2_REDUCED_OPTIMIZATION="COL_IXSCAN_ALL_V1133 OFF" -im option can be used, BUT Static sql will need to be rebound and already compiled dynamic sql re-compiled as well. | |
Solution | |
Workaround | |
**************************************************************** * USERS AFFECTED: * * BLU * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to 11.5 FP7 or later * **************************************************************** | |
Comment | |
Upgrade to 11.5 FP7 or later | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 23.04.2021 22.11.2021 09.12.2021 |
Problem solved at the following versions (IBM BugInfos) | |
Problem solved according to the fixlist(s) of the following version(s) |