Re: Hardware recommendations to scale to silly load - Mailing list pgsql-performance

From Matt Clark
Subject Re: Hardware recommendations to scale to silly load
Date
Msg-id OAEAKHEHCMLBLIDGAFELGEHIDHAA.matt@ymogen.net
Whole thread Raw
In response to Re: Hardware recommendations to scale to silly load  (Ron Johnson <ron.l.johnson@cox.net>)
List pgsql-performance
>     SELECT <blah>
>     IF <some circumstance that happens about 1/8th of the time>
>         BEGIN
>             INSERT
>                or
>             UPDATE
>         COMMIT;
>
> He says his current h/w peaks at 1/10th that rate.
>
> My question is: is that current peak rate ("300 inserts/updates
> *or* 2500 selects") based upon 1 connection, or many connections?
> With 4 CPUs, and a 4 disk RAID10, I wouldn't be surprised if 4 con-
> current connections gives the optimum speed.

Well it's more like each user interaction looks like:

    SELECT
    SELECT
    SELECT
    SELECT
    SELECT
    SELECT
    INSERT
    SELECT
    SELECT
    SELECT
    SELECT
    INSERT
    SELECT
    SELECT
    SELECT
    UPDATE
    SELECT
    SELECT
    UPDATE
    SELECT

And concurrency is very high, because it's a web app, and each httpd has one connection to PG, and there can be
hundredsof active 
httpd processes.  Some kind of connection pooling scheme might be in order when there are that many active clients.
Anyviews? 



pgsql-performance by date:

Previous
From: Tom Lane
Date:
Subject: Re: Selecting random rows efficiently
Next
From: "Matt Clark"
Date:
Subject: Re: Hardware recommendations to scale to silly load