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Received: by postgres.Berkeley.EDU (5.61/1.29)
	id AA11676; Tue, 21 Jul 92 11:52:23 -0700
Message-Id: <9207211852.AA11676@postgres.Berkeley.EDU>
From: postarch (Postgres Mailing Archive)
Subject: Re: null and simple retrieve times
To: postgres@postgres.berkeley.edu
Sender: pg_adm@postgres.berkeley.edu
Reply-To: mer@postgres.berkeley.edu
In-Reply-To: Your message of "Wed, 08 Jul 92 09:05:12 PDT."
             <9207081605.AA09904@postgres.Berkeley.EDU> 
Date: Tue, 21 Jul 92 11:52:11 PDT

you write:
> 
> Does anyone out there who knows how to use libpq have any data about
> how long postgres takes to do a null query and a single tuple fetch?
> 
> example null query - "retrieve (x = 1)" 
> example single tuple fetch - "retrieve (emp.all) where emp.id = 123"

The execution times for both of these queries will be very dependent on
whether POSTGRES is warm or cold (e.g. is this the first query or
have several other queries been run?).  POSTGRES does many cache lookups
on intialization, and every miss means we have to go to disk.


Jeff Meredith
mer@postgres.berkeley.edu