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

Re: Abnormal performance difference between Postgres and MySQL

From: Farhan Husain <russoue(at)gmail(dot)com>
To: Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>
Cc: Robert Haas <robertmhaas(at)gmail(dot)com>, pgsql-performance(at)postgresql(dot)org
Subject: Re: Abnormal performance difference between Postgres and MySQL
Date: 2009-02-25 21:38:10
Message-ID: 3df32b6d0902251338p37159d6dj33f01917600db830@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-performance
On Wed, Feb 25, 2009 at 3:35 PM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>wrote:

> On Wed, Feb 25, 2009 at 2:32 PM, Farhan Husain <russoue(at)gmail(dot)com> wrote:
> >
> > On Wed, Feb 25, 2009 at 3:30 PM, Robert Haas <robertmhaas(at)gmail(dot)com>
> wrote:
> >>
> >> On Wed, Feb 25, 2009 at 3:44 PM, Farhan Husain <russoue(at)gmail(dot)com>
> wrote:
> >> > Initially, it was the default value (32MB). Later I played with that
> >> > value
> >> > thinking that it might improve the performance. But all the values
> >> > resulted
> >> > in same amount of time.
> >>
> >> Well, if you set it back to what we consider to be a reasonable value,
> >> rerun EXPLAIN ANALYZE, and post that plan, it might help us tell you
> >> what to do next.
> >>
> >> ...Robert
> >
> > Right now I am running the query again with 32MB work_mem. It is taking a
> > long time as before. However, I have kept the following values unchanged:
> >
> > shared_buffers = 32MB                   # min 128kB or
> max_connections*16kB
>
> That's REALLY small for pgsql.  Assuming your machine has at least 1G
> of ram, I'd set it to 128M to 256M as a minimum.
>

As I wrote in a previous email, I had the value set to 1792MB (the highest I
could set) and had the same execution time. This value is not helping me to
bring down the execution time.

-- 
Mohammad Farhan Husain
Research Assistant
Department of Computer Science
Erik Jonsson School of Engineering and Computer Science
University of Texas at Dallas

In response to

Responses

pgsql-performance by date

Next:From: Claus GuttesenDate: 2009-02-25 21:39:56
Subject: Re: Abnormal performance difference between Postgres and MySQL
Previous:From: Robert HaasDate: 2009-02-25 21:36:03
Subject: Re: Abnormal performance difference between Postgres and MySQL

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