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Problem IT33629
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Status: Closed |
QUERY PICKS A SLOWER PATH IF THERE IS A LARGE DS_TOTAL_MEMORY VALUE BEING USED.
|
| product: |
INFORMIX SERVER / 5725A3900 / C10 - IDS 12.10 |
| Problem description: |
The query in question consists of a select against one view but
this view expands into many other views (some of these views are
themselves views) and some of these view are selects which
contain union's and left joins.
This query ran in about one minute when on 12.10.FC1 but after
migration it was taking in the region of 45-50 minutes.
It looks like a large value in DS_TOTAL_MEMORY alters the
optimizer into using a slower path and having this set to a
lower value (or zero) results in the query completing again
within one minute. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* Users of Informix Server prior to 12.10.xC15 and 14.10.xC5. *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to Informix Server 12.10.xC15 (when available) or *
* 14.10.xC5. *
**************************************************************** |
| Local Fix: |
|
| Solution |
|
| Workaround |
****************************************************************
* USERS AFFECTED: *
* Users of Informix Server prior to 12.10.xC15 and 14.10.xC5. *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to Informix Server 12.10.xC15 (when available) or *
* 14.10.xC5. *
**************************************************************** |
| Comment |
Fixed in Informix Server 12.10.xC15 and 14.10.xC5. |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 21.07.2020
06.01.2021
06.01.2021 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
