Re: [PATCH] explain sortorder

"Timmer, Marius" <marius.timmer@uni-muenster.de> writes:
> We think, you wanted to switch to DESC behavior 
> (print out NULLS FIRST) in cases, where
> �USING� uses an operator which is considered to be
> a DESC operator.

Right, because that's how addTargetToSortList() would parse it.

> But get_equality_op_for_ordering_op is called in
> cases, where reverse is false, but
> the part
> if (reverse)
>             *reverse = (strategy == BTGreaterStrategyNumber);
> never changes this to true?

Sorry, not following?  It's true that what I added to explain.c doesn't
worry too much about the possibility of get_ordering_op_properties()
failing --- that really shouldn't happen for something that was previously
accepted as a sorting operator.  But if it does, "reverse" will just be
left as false, so the behavior will anyway be unsurprising I think.
We could alternatively make it throw a "cache lookup failed" error but
I'm not sure how that makes anyone's life better.
        regards, tom lane