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Message-ID: <43C682F5.4000001@gmail.com>
Date: Thu, 12 Jan 2006 17:25:25 +0100
From: =?ISO-8859-2?Q?Sz=FBcs_G=E1bor?= <surrano@gmail.com>
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To: pgsql-performance@postgresql.org
Subject: Re: Throwing unnecessary joins away
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Dear Tom,

Not sure about Otto's exact problem, but he did mention views, and I'd feel 
more comfortable if you told me that view-based queries are re-planned based 
on actual conditions etc. Are they?

Also, if you find it unlikely (or very rare) then it might be a configurable 
parameter. If someone finds it drastically improving (some of) their 
queries, it'd be possible to enable this feature in expense of extra planner 
cycles (on all queries).

What I'd be concerned about, is whether the developers' time spent on this 
feature would worth it. :)

--
G.


On 2006.01.12. 16:53, Tom Lane wrote:
> =?ISO-8859-1?Q?Ott=F3_Havasv=F6lgyi?= <havasvolgyi.otto@gmail.com> writes:
>> As far as I know SQL Server has some similar feature. It does not join
>> if not necessary, more exactly: if the result would be the same if it
>> joined the table.
> 
> I find it really really hard to believe that such cases arise often
> enough to justify having the planner spend cycles checking for them.
> 
> 			regards, tom lane