On 04/05/2017 05:41 PM, Andres Freund wrote: > On 2017-04-05 17:22:34 -0400, Tom Lane wrote: >> Andres Freund <andres@anarazel.de> writes: >>> I'd like some input from other committers whether we want this. I'm >>> somewhat doubtful, but don't have particularly strong feelings. >> I don't really want to expose the workings of the plancache at user level. >> The heuristics it uses certainly need work, but it'll get hard to change >> those once there are SQL features depending on it. >> >> Also, as you note, there are debatable design decisions in this particular >> patch. There are already a couple of ways in which control knobs can be >> attached to plgsql functions (i.e. custom GUCs and the comp_option stuff), >> so why is this patch wanting to invent yet another fundamental mechanism? >> And I'm not very happy about it imposing a new reserved keyword, either. >> >> A bigger-picture question is why we'd only provide such functionality >> in plpgsql, and not for other uses of prepared plans. >> >> Lastly, it doesn't look to me like the test cases prove anything at all >> about whether the feature does what it's claimed to. > That echoes my perception - so let's move this to the next CF? It's not > like this patch has been pending for very long. >
Or just Return with Feedback.
ISTM before we revisit this we need agreement on a design.
I am open to any ideas - there are some my start points
1. the possibility to disable plan cache is real request
2. can be useful if we are able to control plan cache inside function - the mix of settings is real case too
3. GUC are useless - nobody would to disable plan cache globally
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 invite any discussion now or in start of new release cycle.
Regards
Pavel
cheers andrew
-- Andrew Dunstan https://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
