Re: Suppressing unused subquery output columns

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Rod Taylor <rod(dot)taylor(at)gmail(dot)com>
Cc: pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Suppressing unused subquery output columns
Date: 2014-06-06 02:54:16
Message-ID: 1210.1402023256@sss.pgh.pa.us
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Rod Taylor <rod(dot)taylor(at)gmail(dot)com> writes:
> On Thu, Jun 5, 2014 at 10:27 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I'm not entirely convinced that it's worth the extra planning cycles,
>> though. Given the small number of complaints to date, it might not
>> be worth doing this. Thoughts?

> Would this avoid execution of expensive functions in views when their
> output is discarded?

Yes, as long as they're not marked volatile and don't return sets.

regards, tom lane

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