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

Re: Any better plan for this query?..

From: "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
To: "Dimitri" <dimitrik(dot)fr(at)gmail(dot)com>,"Robert Haas" <robertmhaas(at)gmail(dot)com>
Cc: "Simon Riggs" <simon(at)2ndquadrant(dot)com>,"Alvaro Herrera" <alvherre(at)commandprompt(dot)com>,"Merlin Moncure" <mmoncure(at)gmail(dot)com>,"Dimitri Fontaine" <dfontaine(at)hi-media(dot)com>,"Aidan Van Dyk" <aidan(at)highrise(dot)ca>,"PostgreSQL Performance" <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Any better plan for this query?..
Date: 2009-05-12 15:46:37
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-performance
Dimitri <dimitrik(dot)fr(at)gmail(dot)com> wrote:
> Of course the Max throughput is reached on the number of users equal
> to 2 * number of cores
I'd expect that when disk I/O is not a significant limiting factor,
but I've seen a "sweet spot" of (2 * cores) + (effective spindle
count) for loads involving a lot of random I/O.
> So, do I really need a pooler to keep 256 users working??
I have seen throughput fall above a certain point when I don't use a
connection pooler.  With a connection pooler which queues requests
when all connections are busy, you will see no throughput degradation
as users of the pool are added.  Our connection pool is in our
framework, so I don't know whether pgbouncer queues requests. 
(Perhaps someone else can comment on that, and make another suggestion
if it doesn't.)

In response to

pgsql-performance by date

Next:From: Joshua D. DrakeDate: 2009-05-12 16:07:59
Subject: Re: Any better plan for this query?..
Previous:From: DimitriDate: 2009-05-12 15:41:14
Subject: Re: What is the most optimal config parameters to keep stable write TPS ?..

Privacy Policy | About PostgreSQL
Copyright © 1996-2018 The PostgreSQL Global Development Group