Skip site navigation (1) Skip section navigation (2)

Re: nested select query failing

From: "amol" <amol(at)mithi(dot)com>
To: <pgsql-performance(at)postgresql(dot)org>
Subject: Re: nested select query failing
Date: 2003-05-21 10:16:00
Message-ID: 000a01c31f81$fa45da70$2e00a8c0@amol (view raw or flat)
Thread:
Lists: pgsql-performance
Hi Tom,
U are great. As you have said, one item was numeric and another serial
 integer ) so it was applying seq scan. Thank you very much for your help
everybody.

regards,
Amol

----- Original Message -----
From: "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "amol" <amol(at)mithi(dot)com>
Cc: <pgsql-performance(at)postgresql(dot)org>
Sent: Tuesday, May 20, 2003 8:48 PM
Subject: Re: [PERFORM] nested select query failing


> "amol" <amol(at)mithi(dot)com> writes:
> > explain analyze select attached_info.id from attached_tag_list,
> > attached_info
> > where
> >          attached_tag_list.attached_tag = 265
> >          and
> >          attached_tag_list.id = attached_info.id
>
> > NOTICE:  QUERY PLAN:
>
> > Nested Loop  (cost=0.00..165349.50 rows=114 width=16) (actual
> > time=117.14..8994.60 rows=15 loops=1)
> >   ->  Index Scan using ix_attached_tag_list_id on attached_tag_list
> > (cost=0.00..111.13 rows=96 width=12) (actual time=0.12..0.66 rows=15
> > loops=1)
> >   ->  Seq Scan on attached_info  (cost=0.00..1211.53 rows=33553 width=4)
> > (actual time=3.67..197.98 rows=33553 loops=15)
> > Total runtime: 8994.92 msec
>
> > - I have already indexed attached_info on id using following query
> > CREATE  INDEX attached_info_Index_1 ON attached_info(id) ;
>
> Hm.  I'd have expected an index scan too.  Maybe the two id columns are
> not of the same datatype?
>
> regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 6: Have you searched our list archives?
>
> http://archives.postgresql.org
>
>


In response to

pgsql-performance by date

Next:From: Ron JohnsonDate: 2003-05-21 14:54:34
Subject: Re: postgres on a beowulf? (AMD)opteron?
Previous:From: Eugene FokinDate: 2003-05-21 07:19:03
Subject: Re: 7.3.2 vs 7.1.2

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group