Informix - Problem description
Problem IT17264 | Status: Closed |
SELECT FIRST N WITH ORDER BY RETURNS THE WRONG NUMBER OF ROWS IFTHE QUERY PLAN USES INDEX-SELF JOIN | |
product: | |
INFORMIX SERVER / 5725A3900 / C10 - IDS 12.10 | |
Problem description: | |
A SELECT FIRST N query with ORDER BY will return either 0 or the wrong number of rows if the query plan uses index-self join on index fragmented by range. | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * Users of 12.10.xC1 through 12.10.xC7. * **************************************************************** * PROBLEM DESCRIPTION: * * A query may produce incorrect results under the following * * conditions: * * - Query on a single table, with an order by clause with * * descending order on a column that leads an index (ascending * * order on lead key) * * - the index is a composite index with at least two index * * keys * * - the first index key column has a small number of * * distinct values, and update statistics medium or high has * * been run on the leading key column * * - there exists a predicate on the 2nd index key column * * which selects a small fraction of the table * * - index self-join is being used to access the table, with * * the index being traversed in reverse order * **************************************************************** * RECOMMENDATION: * * Update to IBM Informix Server 12.10.xC8 * **************************************************************** | |
Local Fix: | |
Solution | |
Workaround | |
not known / see Local fix | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 28.09.2016 09.12.2016 09.12.2016 |
Problem solved at the following versions (IBM BugInfos) | |
12.10.xC8 | |
Problem solved according to the fixlist(s) of the following version(s) |