From: Christopher Petrilli <petrilli@gmail.com>
To: PFC <lists@boutiquenumerique.com>
To: Vivek Khera <vivek@khera.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-performance@postgresql.org
Subject: Re: Impact of checkpoint_segments under continual load conditions
Date: Tue, 19 Jul 2005 11:44:00 -0400
Message-ID: <59d991c4050719084460b376f1@mail.gmail.com> (raw)
In-Reply-To: <op.st52tvunth1vuj@localhost>
References: <59d991c4050717100874c08a86@mail.gmail.com>
<A50B8A1F-71A1-4F63-A5F4-1AA58F89557D@khera.org>
<59d991c405071811457ccdd3f1@mail.gmail.com>
<16394.1121715156@sss.pgh.pa.us>
<59d991c405071812342e290f57@mail.gmail.com>
<16794.1121718743@sss.pgh.pa.us>
<59d991c405071907482bb0689b@mail.gmail.com>
<op.st52tvunth1vuj@localhost>
On 7/19/05, PFC <lists@boutiquenumerique.com> wrote:
>
> What happens if, say at iteration 6000 (a bit after the mess starts), you
> pause it for a few minutes and resume. Will it restart with a plateau like
> at the beginning of the test ? or not ?
Not sure... my benchmark is designed to represent what the database
will do under "typical" circumstances, and unfortunately these are
typical for the application. However, I can see about adding some
delays, though multiple minutes would be absurd in the application.
Perhaps a 5-10 second day? Would that still be interesting?
> What if, during this pause, you disconnect and reconnect, or restart the
> postmaster, or vacuum, or analyze ?
Well, I don't have the numbers any more, but restarting the postmaster
has no effect, other than the first few hundreds COPYs are worse than
anything (3-4x slower), but then it goes back to following the trend
line. The data in the chart for v8.0.3 includes running pg_autovacuum
(5 minutes).
Chris
--
| Christopher Petrilli
| petrilli@gmail.com
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To: pgsql-performance@postgresql.org
Cc: petrilli@gmail.com, lists@boutiquenumerique.com, vivek@khera.org, tgl@sss.pgh.pa.us
Subject: Re: Impact of checkpoint_segments under continual load conditions
In-Reply-To: <59d991c4050719084460b376f1@mail.gmail.com>
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