From: Tom Lane <tgl@sss.pgh.pa.us>
To: Nolan Cafferky <Nolan.Cafferky@rbsinteractive.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Cluster vs. non-cluster query planning
Date: Mon, 01 May 2006 19:35:02 -0400
Message-ID: <20934.1146526502@sss.pgh.pa.us> (raw)
In-Reply-To: <445678B1.9050908@rbsinteractive.com>
References: <445644F9.2020708@rbsinteractive.com>
<44566612.8020709@rbsinteractive.com>
<8044.1146515444@sss.pgh.pa.us>
<445678B1.9050908@rbsinteractive.com>
Nolan Cafferky <Nolan.Cafferky@rbsinteractive.com> writes:
> But, I'm guessing that random_page_cost = 1 is not a realistic value.
Well, that depends. If all your data can be expected to fit in memory
then it is a realistic value. (If not, you should be real careful not
to make performance decisions on the basis of test cases that *do* fit
in RAM...)
In any case, if I recall your numbers correctly you shouldn't need to
drop it nearly that far to get the thing to make the right choice.
A lot of people run with random_page_cost set to 2 or so.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, Nolan.Cafferky@rbsinteractive.com
Subject: Re: Cluster vs. non-cluster query planning
In-Reply-To: <20934.1146526502@sss.pgh.pa.us>
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