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From: Steinar H. Gunderson <sgunderson@bigfoot.com>
To: pgsql-performance@postgresql.org
Subject: Re: Cursors and different settings for default_statistics_target
Date: Tue, 1 Apr 2008 21:57:44 +0200
Message-ID: <20080401195744.GA22880@uio.no> (raw)
In-Reply-To: <9999.1207068123@sss.pgh.pa.us>
References: <B710F3299F04664DB6B37C258FDEEB940158AFF9@FABAMAIL.fabagl.fabasoft.com>
	<2798.1207063805@sss.pgh.pa.us>
	<B710F3299F04664DB6B37C258FDEEB940158B0E9@FABAMAIL.fabagl.fabasoft.com>
	<9629.1207066619@sss.pgh.pa.us>
	<B710F3299F04664DB6B37C258FDEEB940158B0FC@FABAMAIL.fabagl.fabasoft.com>
	<9999.1207068123@sss.pgh.pa.us>

On Tue, Apr 01, 2008 at 12:42:03PM -0400, Tom Lane wrote:
>> That's CURSOR_OPT_FAST_PLAN and isn't it? Our application reads the full
>> results of most cursors.
> Just out of curiosity, why use a cursor at all then?

This isn't the same scenario as the OP, but I've used a cursor in cases where
I cannot keep all of the dataset in memory at the client at once, but I _can_
coerce it down to a more manageable size as it comes in.

I don't know if a cursor is the only way to do this (short of making a custom
function inside Postgres of some sort), but it seems to be the simplest way
in libpqxx, at least.

/* Steinar */
-- 
Homepage: http://www.sesse.net/



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