Re: proposal: plpgsql pragma statement

čt 6. 12. 2018 v 17:27 odesílatel Robert Haas <robertmhaas(at)gmail(dot)com>
napsal:

> On Tue, Dec 4, 2018 at 12:13 PM Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
> wrote:
> > I wrote plpgsql_check https://github.com/okbob/plpgsql_check.
> >
> > It is working well, but because it does static analyse only, sometimes
> it can produces false alarms or it should to stop a analyse, because there
> are not necessary data.
> >
> > https://github.com/okbob/plpgsql_check/issues/36
> >
> > I see one possible solution in introduction of pragma statement with
> syntax:
> >
> > PRAGMA keyword [content to semicolon];
> >
> > The pragma has a relation to following statement. So the issue 36 can be
> solved by pragma
> >
> > PRAGMA cmdtype CREATE;
> > EXECUTE format('CREATE TABLE xxx ...
> >
> > The PRAGMA statement does nothing in runtime. It works only in compile
> time, and add a pair of key, value to next non pragma statement. This
> information can be used by some plpgsql extensions.
> >
> > What do you think about this proposal?
>
> I think it's commandeering PRAGMA for a fairly narrow purpose. It's
> hardly unimaginable that someone in future might want a PRAGMA that
> does change runtime behavior, or that affects something other than the
> statement which immediately follows.
>
> I don't see a big problem allowing some kind of annotation that
> plpgsql_check can easily access, and I don't even mind it being called
> PRAGMA. But I don't think it should foreclose unrelated uses of
> PRAGMA which somebody might want to introduce in the future.
>

The most simple (and probably one possible) implementation is plpgsql
statement - because I would not to modify SQL lexer.

I am thinking so PRAGMA statement is natural due semantic and usage in Ada,
but I am opened any proposals.

Regards

Pavel

> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company
>