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 | | From: | andrzej | | Subject: | BUG #1408: don't see index | | Date: | Tue, 18 Jan 2005 09:01:29 GMT |
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The following bug has been logged online:
Bug reference: 1408
Logged by: andrzej
Email address: wppl16@wp.pl
PostgreSQL version: 8.0.0-rc5
Operating system: windows XP
Description: don't see index
Details:
Create table t1
(
v varchar(5) not null,
m varchar(20),
d date,
l varchar(10),
primary key(v)
);
explain select * from t1 where v='abc'
result:
Seq Scan on t1 (....
Filter:((v)::text='abc'::text)
DON'T SEE INDEX PKEY ???????!!!!
but Postgres 7.4.2 Linux
explain select * from t1 where v='abc'
result:
Index Scan using t1_pkey on t1(...
Index Cond((v)::text='abc'::text)
SEE INDEX PKEY OK !!!!!
---------------------------(end of broadcast)---------------------------
TIP 8: explain analyze is your friend
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| | From: | Bruno Wolff III | | Subject: | Re: BUG #1408: don't see index | | Date: | Thu, 20 Jan 2005 14:28:45 -0600 |
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| On Tue, Jan 18, 2005 at 09:01:29 +0000,
andrzej wrote:
>
> The following bug has been logged online:
>
> Bug reference: 1408
> Logged by: andrzej
> Email address: wppl16@wp.pl
> PostgreSQL version: 8.0.0-rc5
> Operating system: windows XP
> Description: don't see index
> Details:
>
> Create table t1
> (
> v varchar(5) not null,
> m varchar(20),
> d date,
> l varchar(10),
> primary key(v)
> );
>
> explain select * from t1 where v='abc'
> result:
> Seq Scan on t1 (....
> Filter:((v)::text='abc'::text)
> DON'T SEE INDEX PKEY ???????!!!!
>
> but Postgres 7.4.2 Linux
> explain select * from t1 where v='abc'
> result:
> Index Scan using t1_pkey on t1(...
> Index Cond((v)::text='abc'::text)
> SEE INDEX PKEY OK !!!!!
This probably isn't a bug. In some circumstances a sequential scan is faster
than an index scan.
How many rows are in this table?
Have you run an ANALYZE on the table?
---------------------------(end of broadcast)---------------------------
TIP 4: Don't 'kill -9' the postmaster
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