From: | David Kerr <dmk(at)mr-paradox(dot)net> |
---|---|
To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
Cc: | pgsql-performance(at)postgresql(dot)org |
Subject: | Re: Very high effective_cache_size == worse performance? |
Date: | 2010-04-20 18:47:27 |
Message-ID: | 20100420184727.GE53489@mr-paradox.net |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
On Tue, Apr 20, 2010 at 02:15:19PM -0400, Robert Haas wrote:
- On Tue, Apr 20, 2010 at 2:03 PM, David Kerr <dmk(at)mr-paradox(dot)net> wrote:
- > that thought occured to me while I was testing this. I ran a vacuumdb -z
- > on my database during the load and it didn't impact performance at all.
-
- The window to run ANALYZE usefully is pretty short. If you run it
- before the load is complete, your stats will be wrong. If you run it
- after the select statements that hit the table are planned, the
- updated stats won't arrive in time to do any good.
right, but i'm loading 20 million records in 1000 record increments. so
the analyze should affect all subsequent increments, no?
- > I did turn on log_min_duration_statement but that caused performance to be unbearable,
- > but i could turn it on again if it would help.
-
- I think you need to find a way to identify exactly which query is
- running slowly. You could sit there and run "select * from
- pg_stat_activity", or turn on log_min_duration_statement, or have your
- application print out timestamps at key points, or some other
- method...
I'm on it.
Dave
From | Date | Subject | |
---|---|---|---|
Next Message | Scott Marlowe | 2010-04-20 19:22:36 | Re: Very high effective_cache_size == worse performance? |
Previous Message | David Kerr | 2010-04-20 18:46:14 | Re: Very high effective_cache_size == worse performance? |