Informix - Problem description
Problem IT27549 | Status: Closed |
WRONG RESULTS POSSIBLE WITH SKIP SCAN (MULTI-INDEX) QUERY PATH ON IN-PLACE ALTERED TABLES | |
product: | |
INFORMIX SERVER / 5725A3900 / C10 - IDS 12.10 | |
Problem description: | |
When you run an SQL query against a table which has undergone in-place alters you may observe wrong results when a "skip scan" (multi-index) path is choosen by the optimizer and all pages of the table are of the current version. The example is a query like select {+MULTI_INDEX(tab1 idx1)} count(*) from tab1 where c2 = 'text to fill space' and c3 between '01.01.1970' and '31.12.9999'; resulting in a query plan QUERY: (OPTIMIZATION TIMESTAMP: 04-26-2018 14:02:20) ------ select {+MULTI_INDEX(tab1 idx1)} count(*) from tab1 where c2 = 'text to fill space' and c3 between '01.01.1970' and '31.12.9999' DIRECTIVES FOLLOWED: MULTI_INDEX ( tab1 idx1 ) DIRECTIVES NOT FOLLOWED: Estimated Cost: 6 Estimated # of Rows Returned: 1 1) usera.tab1: INDEX PATH (SKIP SCAN) Filters: usera.tab1.c2 = 'text to fill space' (1) Index Name: usera.idx1 Index Keys: c3 (Serial, fragments: ALL) Lower Index Filter: usera.tab1.c3 >= 01.01.1970 Upper Index Filter: usera.tab1.c3 | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * Users of IDS versions older than 12.10.xC12. * **************************************************************** * PROBLEM DESCRIPTION: * * Wrong results possible with skip scan (multi-index) query * * path on in-place altered tables. * **************************************************************** * RECOMMENDATION: * **************************************************************** | |
Local Fix: | |
Solution | |
Workaround | |
not known / see Local fix | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 26.12.2018 04.10.2019 04.10.2019 |
Problem solved at the following versions (IBM BugInfos) | |
12.10.xC12 | |
Problem solved according to the fixlist(s) of the following version(s) |