Re: wCTE behaviour

Marko Tiikkaja <marko.tiikkaja@cs.helsinki.fi> writes:
> I fixed an issue with the portal logic, and now we use 
> PORTAL_ONE_RETURNING for wCTE queries, even if the main query is not a 
> DML or does not have RETURNING.  This also means that we materialize the 
> results of the main query sometimes unnecessarily, but that doesn't look 
> like an easy thing to fix.  PORTAL_ONE_RETURNING as a name is also a bit 
> misleading now, so maybe that needs changing..

Why is it necessary to hack the portal logic at all?  The patch seems to
work for me without that.  (I've fixed quite a few bugs though, so maybe
what this is really doing is masking a problem elsewhere.)

Also, why are we forbidding wCTEs in cursors?  Given the current
definitions, that case seems to work fine too: the wCTEs will be
executed as soon as you fetch something from the cursor.  Are you
just worried about not allowing a case that might be hard to support
later?
        regards, tom lane