Re: Script to compute random page cost

Nick Fankhauser wrote:
> Hi again-
> 
> I bounced these numbers off of Ray Ontko here at our shop, and he pointed
> out that random page cost is measured in multiples of a sequential page
> fetch. It seems almost impossible that a random fetch would be less
> expensive than a sequential fetch, yet we all seem to be getting results <
> 1. I can't see anything obviously wrong with the script, but something very
> odd is going.

OK, new version at:
ftp://candle.pha.pa.us/pub/postgresql/randcost

What I have done is to take all of the computation stuff out of the
timed loop so only the 'dd' is done in the loop.

I am getting a 1.0 for random pages cost with this new code, but I don't
have much data in the database so it is very possible I have it all
cached.  Would others please test it?

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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