From: Tom Lane <tgl@sss.pgh.pa.us>
To: Heikki Linnakangas <hlinnaka@iki.fi>
cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: eval_const_expresisions and ScalarArrayOpExpr
In-reply-to: <4b14a9a5-01c2-4042-3ec9-cf27149302a5@iki.fi>
References: <3be3b82c-e29c-b674-2163-bf47d98817b1@iki.fi>
 <23186.1494516060@sss.pgh.pa.us>
 <4b14a9a5-01c2-4042-3ec9-cf27149302a5@iki.fi>
Comments: In-reply-to Heikki Linnakangas <hlinnaka@iki.fi>
	message dated "Thu, 11 May 2017 19:20:55 +0300"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <22028.1494605094.1@sss.pgh.pa.us>
Date: Fri, 12 May 2017 12:04:54 -0400
Message-ID: <22029.1494605094@sss.pgh.pa.us>
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org

Heikki Linnakangas <hlinnaka@iki.fi> writes:
> On 05/11/2017 06:21 PM, Tom Lane wrote:
>> Yeah, I think it's a lack-of-round-tuits situation.  Your patch reminds
>> me of a more ambitious attempt I made awhile back to reduce the amount
>> of duplicative boilerplate in eval_const_expressions.  I think I wrote
>> it during last year's beta period, stashed it because I didn't feel like
>> arguing for applying it right then, and then forgot about it.

> Hmph, now we're almost in beta period again. :-(.

Actually, I now remember that I wrote that while at Salesforce (because
they'd run into the problem that constant ArrayRef expressions weren't
simplified).  So that means it's been languishing in a git branch for
*two* years.  I'm kind of inclined to push it before it gets forgotten
again ;-)

Looking at the patch, it still seems solid, but I remember that one
thing I was concerned about was whether the more generalized code
was any slower.  Not sure about a good test case to measure that
though --- const-simplification isn't a large chunk of most workloads.

			regards, tom lane


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers