PostgreSQL Bugs - BUG #1681: Selection problem

Author

BUG #1681: Selection problem

fremaux

2005-05-26, 11:23 am

The following bug has been logged online:

Bug reference: 1681
Logged by: fremaux
Email address: benjamin.fremaux@sofrecom.com
PostgreSQL version: 7.2.2
Operating system: Linux kernel 2.4.6.19-mdk
Description: Selection problem
Details:

following query :
SELECT list.group_artifact_id, list.name
FROM artifact_group_list list
WHERE (list. group_artifact_id=16
7)

returns 2 lines where the first list.group_artifact_id equals "165". The
problem is that the only lines that have to be returned are the ones with
list. group_artifact_id=16
7

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Michael Fuhr

2005-05-26, 11:24 am

On Thu, May 26, 2005 at 02:50:44PM +0100, fremaux wrote:
>
> PostgreSQL version: 7.2.2

PostgreSQL 7.2.2 is almost three years old -- consider upgrading
to 7.2.8, or better yet, 8.0.3.

> SELECT list.group_artifact_id, list.name
> FROM artifact_group_list list
> WHERE (list. group_artifact_id=16
7)
>
> returns 2 lines where the first list.group_artifact_id equals "165". The
> problem is that the only lines that have to be returned are the ones with
> list. group_artifact_id=16
7

Could you post the query results and the query's EXPLAIN ANALYZE
output? Do you have an index on group_artifact_id? If so, and if
EXPLAIN ANALYZE shows that the query uses the index, what happens
if you set enable_indexscan to off? What type is group_artifact_id?
How often do you vacuum, analyze, and/or reindex the table?

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/

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Michael Fuhr

2005-05-27, 11:24 am

[Please copy the mailing list on replies so others can participate
in and learn from the discussion.]

On Fri, May 27, 2005 at 10:08:20AM +0200, FREMAUX Benjamin SOFRECOM wrote:
>
> I have effectively an index (PK) on list.group_artifact_id. I solved the
> problem with an index rebuild.

A reindex might have provided an immediate fix, but it probably
didn't solve the problem; it might happen again. I don't know if
the problem still exists in later releases in the 7.2 branch, but
in any case I'd recommend using something newer than 7.2.2. A
number of bugs have been fixed since then; see the Release Notes
for details.

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/

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FREMAUX Benjamin SOFRECOM

2005-05-31, 11:24 am

Thank you

Michael Fuhr a écrit :

>[Please copy the mailing list on replies so others can participate
>in and learn from the discussion.]
>
>On Fri, May 27, 2005 at 10:08:20AM +0200, FREMAUX Benjamin SOFRECOM wrote:
>
>
>
>A reindex might have provided an immediate fix, but it probably
>didn't solve the problem; it might happen again. I don't know if
>the problem still exists in later releases in the 7.2 branch, but
>in any case I'd recommend using something newer than 7.2.2. A
>number of bugs have been fixed since then; see the Release Notes
>for details.
>
>
>

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