Re: Configuring for maximum memory usage - Mailing list pgsql-performance

From Christiaan Willemsen
Subject Re: Configuring for maximum memory usage
Date
Msg-id 4909D989.5020905@technocon.com
Whole thread Raw
In response to Re: Configuring for maximum memory usage  ("Joshua D. Drake" <jd@commandprompt.com>)
Responses Re: Configuring for maximum memory usage  ("Joshua D. Drake" <jd@commandprompt.com>)
List pgsql-performance
Joshua D. Drake wrote:
>
> PostgreSQL is only going to use what it needs. It relies on the OS for
> much of the caching etc...
>
So that would actually mean that I could raise the setting of the ARC
cache to far more than 8 GB? As I said, our database is 250 GB, So I
would expect that postgres needs more than it is using right now...
Several tables have over 500 million  records (obviously partitioned).
At the moment we are doing queries over large datasets, So I would
assume that postgress would need a bit more memory than this..
>
> You are missing effective_cache_size. Try setting that to 32G.
That one was set to 24 GB. But this setting only tells posgres how much
caching it can expect from the OS? This is not actually memory that it
will allocate, is it?
>
> You also didn't mention checkpoint_segments (which isn't memory but
> still important) and default_statistics_target (which isn't memory but
> still important).
>
is at the moment set to:

checkpoint_segments = 40
default_statistics_target is set to default (I think that is 10)

Thanks already,

Christiaan

pgsql-performance by date:

Previous
From: "Joshua D. Drake"
Date:
Subject: Re: Configuring for maximum memory usage
Next
From: "Joshua D. Drake"
Date:
Subject: Re: Configuring for maximum memory usage