Horton

Re: PoC plpgsql - possibility to force custom or generic plan

Tom Lane <tgl@sss.pgh.pa.us>

View thread View on postgr.es
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: Daniel Gustafsson <daniel@yesql.se>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Andrew Dunstan <andrew.dunstan@2ndquadrant.com>, Andres Freund <andres@anarazel.de>, Petr Jelinek <petr.jelinek@2ndquadrant.com>, David Steele <david@pgmasters.net>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Jim Nasby <Jim.Nasby@bluetreble.com>
Date: 2017-09-05T17:38:42Z
Lists: pgsql-hackers 
Pavel Stehule <pavel.stehule@gmail.com> writes:
> 2. what syntax we should to use (if we accept this feature)? There was not
> another proposal if I remember well - The PRAGMA syntax is strong because
> we can very well specify to range where the plans caching will be
> explicitly controlled. It is well readable and static.

The complaint I have about PRAGMA is that it's yet another syntax for
accomplishing pretty much the same thing.  If you don't like the GUC
solution, we've already got the "comp_option" syntax for static options
in plpgsql.  Sure, that's not too pretty, but that's not a good reason
to invent yet another way to do it.

			regards, tom lane

Commits

  1. Add plan_cache_mode setting

  2. Add some noreturn attributes to help static analyzers

  3. document when PREPARE uses generic plans

  4. Redesign the plancache mechanism for more flexibility and efficiency.