From: Szűcs Gábor <surrano@gmail.com>
To: pgsql-performance@postgresql.org
Subject: Re: Throwing unnecessary joins away
Date: Thu, 12 Jan 2006 17:25:25 +0100
Message-ID: <43C682F5.4000001@gmail.com> (raw)
In-Reply-To: <5269.1137081233@sss.pgh.pa.us>
References: <34608c0c0601120418n1af567b9n@mail.gmail.com>
<43C64CFB.9030504@barettadeit.com>
<34608c0c0601120541wd910da3s@mail.gmail.com>
<5269.1137081233@sss.pgh.pa.us>
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
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To: pgsql-performance@postgresql.org
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Subject: Re: Throwing unnecessary joins away
In-Reply-To: <43C682F5.4000001@gmail.com>
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