Re: checkpoint_timeout - Mailing list pgsql-general

From Greg Stark
Subject Re: checkpoint_timeout
Date
Msg-id 87mzsv7zyk.fsf@stark.xeocode.com
Whole thread Raw
In response to Re: checkpoint_timeout  (Bruce Momjian <pgman@candle.pha.pa.us>)
Responses Re: checkpoint_timeout  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-general
Bruce Momjian <pgman@candle.pha.pa.us> writes:

> I don't see something that happens every five minutes as any kind of
> performance problem.   I am not sure what Josh saw that made him want to
> increase that.

I would have thought checkpoint_timeout would be something you would adjust
depending on whether you want even performance (set it low and live with
redundant i/o) or maximum throughput (set it high and live with i/o spikes and
performance dropouts). Does that make sense?

I suspect the origin of this meme might be with those benchmark graphs that
were being posted here that had the checkpoint timeout set to 30m. That seems
to be a bogus setting that's just hiding some of the i/o by postponing it
until after the test ends.

--
greg

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