Re: data on devel code perf dip - Mailing list pgsql-hackers

From Tom Lane
Subject Re: data on devel code perf dip
Date
Msg-id 9736.1123810702@sss.pgh.pa.us
Whole thread Raw
In response to Re: data on devel code perf dip  (Alvaro Herrera <alvherre@alvh.no-ip.org>)
Responses Re: data on devel code perf dip  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-hackers
Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
> In light of this, may I ask whether it makes sense to compare the
> performance of two runs with similar shared_buffer settings?  With
> O_DIRECT, I understand from this manpage that the OS is going to do
> little or no page caching, so shared_buffers should be increased to
> account for this fact.

> Am I missing something?

O_DIRECT is only being used for WAL page writes (or I sure hope so
anyway), so shared_buffers should be irrelevant.
        regards, tom lane


pgsql-hackers by date:

Previous
From: Alvaro Herrera
Date:
Subject: Re: data on devel code perf dip
Next
From: Bruce Momjian
Date:
Subject: Re: data on devel code perf dip