"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Fri, Feb 9, 2018 at 6:23 AM, Michael Paquier <michael@paquier.xyz> wrote:
>> On Fri, Feb 09, 2018 at 12:02:57PM +0100, Pavel Stehule wrote:
>>> Blocking subqueries in CALL parameters is possible solution.
> To me this feels like an interaction between two features that users are
> going to expect to just work.
Meh. It doesn't look significantly different to me than the restriction
that you can't have sub-selects in CHECK expressions, index expressions,
etc. Obviously we need a clean failure like you get for those cases.
But otherwise it's an OK restriction that stems from exactly the same
cause: we do not want to invoke the full planner in this context (and
even if we did, we don't want to use the full executor to execute the
result).
regards, tom lane