Re: PL/pgSQL cursors should get generated portal names by default

Dne po 7. 11. 2022 17:10 uživatel Jan Wieck <jan(at)wi3ck(dot)info> napsal:

> On 11/4/22 19:46, Tom Lane wrote:
> > Jan Wieck <jan(at)wi3ck(dot)info> writes:
> >> I need to do some testing on this. I seem to recall that the naming was
> >> originally done because a reference cursor is basically a named cursor
> >> that can be handed around between functions and even the top SQL level
> >> of the application. For the latter to work the application needs to
> know
> >> the name of the portal.
> >
> > Right. With this patch, it'd be necessary to hand back the actual
> > portal name (by returning the refcursor value), or else manually
> > set the refcursor value before OPEN to preserve the previous behavior.
> > But as far as I saw, all our documentation examples show handing back
> > the portal name, so I'm hoping most people do it like that already.
>
> I was mostly concerned that we may unintentionally break underdocumented
> behavior that was originally implemented on purpose. As long as everyone
> is aware that this is breaking backwards compatibility in the way it
> does, that's fine.
>

In this case I see current behaviors little bit unhappy. It breaks any
recursive call, it can break variable shadowing, so I prefer change. The
possibility of compatibility break is clean, but there is an possibility of
easy fix, and I think I can detect some possibly not compatible usage in
plpgsql_check.

The dependency on current behavior can be probably just for pretty old
application that doesn't use refcursors.

Regards

Pavel

> >
> >> I am currently down with Covid and have trouble focusing. But I hope to
> >> get to it some time next week.
> >
> > Get well soon!
>
> Thanks, Jan
>
>