Horton

Re: Optimze usage of immutable functions as relation

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Alexander Kuzmenkov <a.kuzmenkov@postgrespro.ru>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Aleksandr Parfenov <asp437@gmail.com>, a.bykov@postgrespro.ru, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Antonin Houska <ah@cybertec.at>, Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
Date: 2019-07-08T01:18:21Z
Lists: pgsql-hackers 
On Thu, Mar 21, 2019 at 5:58 AM Alexander Kuzmenkov
<a.kuzmenkov@postgrespro.ru> wrote:
> On 11/16/18 22:03, Tom Lane wrote:
> > A possible fix for this is to do eval_const_expressions() on
> > function RTE expressions at this stage (and then not need to
> > do it later), and then pull up only when we find that the
> > RTE expression has been reduced to a single Const.
>
>
> Attached is a patch that does this, and transforms RTE_FUCTION that was
> reduced to a single Const into an RTE_RESULT.

Hi Alexander,

The July Commitfest is here.  Could we please have a rebase of this patch?

Thanks,

-- 
Thomas Munro
https://enterprisedb.com

Commits

  1. Prevent bogus pullup of constant-valued functions returning composite.

  2. Allow functions-in-FROM to be pulled up if they reduce to constants.