From: | pgsql-bugs(at)postgresql(dot)org |
---|---|
To: | pgsql-bugs(at)postgresql(dot)org |
Subject: | Bug #474: Index using problem |
Date: | 2001-10-05 07:21:01 |
Message-ID: | 200110050721.f957L1i27238@postgresql.org |
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Lists: | pgsql-bugs |
JoE Olcsak (joe78(at)freemail(dot)hu) reports a bug with a severity of 4
The lower the number the more severe it is.
Short Description
Index using problem
Long Description
I have a problem when using indexes under PostgreSQL 7.1.1 ...
The problem is :
I have a field of table ... This is an INT4 type field ... and I
created an index for this field like :
create index idx_of_field on cim(utod_cim_id);
... and I executed a simple query ...
explain select * from cim where utod_cim_id=0;
NOTICE: QUERY PLAN:
Seq Scan on cim (cost=0.00..6555.41 rows=253633 width=118)
EXPLAIN
The query optimizer does not use my index..
I'm executed vacuum analyze command for this table but this not helps me ...
Then I created another index for this field:
create index idx_of_field2 on cim(int4(utod_cim_id));
... and I executed another simple query :
explain select * from cim where int4(utod_cim_id)=0;
NOTICE: QUERY PLAN:
Index Scan using idx_of_field2 on cim (cost=0.00..6499.70 rows=2536 width=118)
EXPLAIN
What is wrong in the first case ?
Sample Code
No file was uploaded with this report
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