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

On Tue, Sep 19, 2017 at 1:37 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Tue, Sep 19, 2017 at 12:45 PM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
>>> You can already set a GUC with function scope.  I'm not getting your
>>> point.
>>
>> yes, it is true. But implementation of #option is limited to PLpgSQL - so
>> there is not any too much questions - GUC is global - there is lot of
>> points:
>>
>> * what is correct impact on PREPARE
>> * what is correct impact on EXECUTE
>> * what should be done if this GUC is changed ..
>
> For better or for worse, as a project we've settled on GUCs as a way
> to control behavior.  I think it makes more sense to try to apply that
> option to new behaviors we want to control than to invent some new
> system.

This seems very sensible.

We also have infrastructure at the SQL level (SET) to manage the GUC.
Tom upthread (for pretty good reasons) extending SET to pl/pgsql
specific scoping but TBH I'm struggling as to why we need to implement
new syntax for this; the only thing missing is being able to scope SET
statements to a code block FWICT.

merlin