Re: Redundant check of em_is_child

On Fri, May 19, 2017 at 3:46 AM, Amit Langote
<Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> wrote:
> In match_eclasses_to_foreign_key_col(), there is this:
>
> if (em->em_is_child)
> continue; /* ignore children here */
>
> ISTM, it might as well be:
>
> Assert(!em->em_is_child); /* no children yet */
>
> That's because, I think it's still too early in query_planner() to be
> expecting any child EC members.

I'm not sure there's really any benefit to this change. In the
future, somebody might want to use the function from someplace later
on in the planner. If the logic as-written would work correctly in
that case now, I can't see why we should turn it into an assertion
failure instead. This isn't really costing us anything, is it?

--
Robert Haas
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