From: "Jean-Pierre Pelletier" <pelletier_32@sympatico.ca>
To: <josh@agliodbs.com>
Sent: Thursday, September 22, 2005 6:37 PM
Subject: Re: [PERFORM] Queries 15 times slower on 8.1 beta 2 than on 8.0
How do I produce an "Index scan plan" ?
----- Original Message -----
From: "Josh Berkus" <josh@agliodbs.com>
To: <pgsql-performance@postgresql.org>
Cc: "Jean-Pierre Pelletier" <pelletier_32@sympatico.ca>; "John Arbash
Meinel" <john@arbash-meinel.com>
Sent: Thursday, September 22, 2005 6:19 PM
Subject: Re: [PERFORM] Queries 15 times slower on 8.1 beta 2 than on 8.0
----- Original Message -----
From: "Josh Berkus" <josh@agliodbs.com>
To: <pgsql-performance@postgresql.org>
Cc: "Jean-Pierre Pelletier" <pelletier_32@sympatico.ca>; "John Arbash
Meinel" <john@arbash-meinel.com>
Sent: Thursday, September 22, 2005 6:19 PM
Subject: Re: [PERFORM] Queries 15 times slower on 8.1 beta 2 than on 8.0
Jean-Pierre,
First off, you're on Windows?
Given that it's *expecting* only one row, I can't understand why it's
using a seq scan ...
it hard to compare ...
--
--Josh
Josh Berkus
Aglio Database Solutions
San Francisco
First off, you're on Windows?
" -> Seq Scan on price p (cost=0.00..11317.75 rows=581475 width=4)
(actual time=0.004..1143.720 rows=581475 loops=1)"
Well, this is your pain point. Can we see the index scan plan on 8.1?(actual time=0.004..1143.720 rows=581475 loops=1)"
Given that it's *expecting* only one row, I can't understand why it's
using a seq scan ...
"Nested Loop Left Join (cost=0.00..11.02 rows=1 width=0) (actual
time=0.000..0.000 rows=1 loops=1)"
" -> Nested Loop Left Join (cost=0.00..5.48 rows=1 width=4) (actual
time=0.000..0.000 rows=1 loops=1)"
"Total runtime: 0.000 ms"
Feh, this looks like the "windows does not report times" bug, which makestime=0.000..0.000 rows=1 loops=1)"
" -> Nested Loop Left Join (cost=0.00..5.48 rows=1 width=4) (actual
time=0.000..0.000 rows=1 loops=1)"
"Total runtime: 0.000 ms"
it hard to compare ...
--
--Josh
Josh Berkus
Aglio Database Solutions
San Francisco