DB2 - Problem description
Problem IT37079 | Status: Closed |
COUNT DISTINCT QUERIES AGAINST COLUMNAR ORGANIZED TABLES COULD RETURN INCORRECT RESULTS | |
product: | |
DB2 FOR LUW / DB2FORLUW / B50 - DB2 | |
Problem description: | |
When running count distinct queries against columnar organized tables, incorrect results could be returned. | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * COUNT DISTINCT QUERIES AGAINST COLUMNAR ORGANIZED TABLES * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description, Please, install the fix. * **************************************************************** * RECOMMENDATION: * * Upgrade to Db2 11.5.6 or higher * **************************************************************** | |
Local Fix: | |
Set the number of CDE threads to 1, as the problem requires 2 or more threads to reproduce. This can be done using several approaches: 1. update db cfg using DFT_DEGREE 1 2. db2set DB2_CDE_THREAD_COUNT=1 3. Or increase the db cfg SORTHEAP setting to reduce the likelihood of hitting the problem, as it reduces the amount of spilling. | |
Solution | |
Workaround | |
**************************************************************** * USERS AFFECTED: * * COUNT DISTINCT QUERIES AGAINST COLUMNAR ORGANIZED TABLES * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description, Please, install the fix. * **************************************************************** * RECOMMENDATION: * * Upgrade to Db2 11.5.6 or higher * **************************************************************** | |
Comment | |
Upgrade to Db2 11.5.6 or higher | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 01.06.2021 17.06.2021 29.06.2021 |
Problem solved at the following versions (IBM BugInfos) | |
Problem solved according to the fixlist(s) of the following version(s) |