Horton

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

Bruce Momjian <bruce@momjian.us>

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From: Bruce Momjian <bruce@momjian.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Pavel Stehule <pavel.stehule@gmail.com>, 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: 2017-09-16T16:55:32Z
Lists: pgsql-hackers 
On Wed, Sep  6, 2017 at 10:43:39AM -0400, Robert Haas wrote:
> helps.  I don't think we can just indefinitely continue to resist
> providing manual control over this behavior on the theory that some
> day we'll fix it.  It's been six years and we haven't made any
> significant progress.  In some cases, a long delay without any
> progress might just point to a lack of effort that should have been
> applied, but in this case I think it's because the problem is
> incredibly hard.

Add to that, we didn't even document the behavior until last year:

	commit fab9d1da4a213fab08fe2d263eedf2408bc4a27a
	Author: Bruce Momjian <bruce@momjian.us>
	Date:   Tue Jun 14 16:11:46 2016 -0400
	
	    document when PREPARE uses generic plans
	
	    Also explain how generic plans are created.
	    Link to PREPARE docs from wire-protocol prepare docs.
	
	    Reported-by: Jonathan Rogers
	
	    Discussion: https://www.postgresql.org/message-id/flat/561E749D.4090301%40socialserve.com

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +

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.