Horton

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

Peter Eisentraut <peter.eisentraut@2ndquadrant.com>

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From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
To: Pavel Stehule <pavel.stehule@gmail.com>, Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Cc: Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>, Petr Jelinek <petr.jelinek@2ndquadrant.com>, David Steele <david@pgmasters.net>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Jim Nasby <Jim.Nasby@bluetreble.com>
Date: 2017-04-08T00:30:59Z
Lists: pgsql-hackers 
On 4/6/17 14:32, Pavel Stehule wrote:
> I like to see any proposals about syntax or implementation.
> 
> Using PRAGMA is one variant - introduced by PLpgSQL origin - Ada
> language. The PRAGMA syntax can be used for PRAGMA autonomous with well
> known syntax. It scales well  - it supports function, block or command
> level.

I had pragmas implemented in the original autonomous transactions patch
(https://www.postgresql.org/message-id/659a2fce-b6ee-06de-05c0-c8ed6a01979e@2ndquadrant.com).
 However, the difference there is that the behavior is lexical, specific
to plpgsql, whereas here you are really just selecting run time
behavior.  So a GUC, and also something that could apply to other
places, should be considered.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

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.