Re: Procedure support improvements

[CC to -hackers]
Dave Cramer wrote:
> On Mon, 26 Aug 2019 at 13:43, Laurenz Albe <[email protected]>
> wrote:
> > Dave Cramer wrote:
> > > As I said, I'd entertain a connection parameter that switched the
> > > CALL to call procedures but ideally you'd complain to the server
> > > folks to make Procedures useful.
> > 
> > Apart from the obvious problem that procedures make life hard for 
> > the JDBC driver, because it does not know if it shall render a call
> > as SELECT or CALL:
> > What is missing in PostgreSQL procedures to make them useful?
> 
> being able to use transactions inside a procedure inside a 
> transaction.

test=> CREATE OR REPLACE PROCEDURE testproc() LANGUAGE plpgsql AS
       $$BEGIN PERFORM 42; COMMIT; PERFORM 'x'; END;$$;
CREATE PROCEDURE
test=> CALL testproc();
CALL
test=> BEGIN;
BEGIN
test=> CALL testproc();
ERROR:  invalid transaction termination
CONTEXT:  PL/pgSQL function testproc() line 1 at COMMIT

Oops.
I find that indeed surprising.

What is the rationale for this?

Yours,
Laurenz Albe