Re: Seq scan on zero-parameters function

Richard Huxton <dev@archonet.com> writes:
> It's not entirely clear to me why this form is different from the other form
> though.

The code that checks for expressions containing unstable functions
doesn't look inside sub-selects.  Arguably this is a bug, but people
were relying on that behavior way back before we had these nice
STABLE/IMMUTABLE tags for functions.  I'm hesitant to change it for
fear of breaking people's apps.

            regards, tom lane