I wrote:
> I'm not wedded to that name, certainly, but it seems like neither
> of these is quite getting at the issue. An EC can be sorted on,
> by definition, but there are some things we don't want to sort
> on till the final output step. I was trying to think of something
> using the terminology "early sort", but didn't much like
> "relation_has_early_sortable_ec_member" or obvious variants of that.
... or, as long as it's returning a boolean, maybe it could be
"relation_can_be_sorted_early" ?
regards, tom lane
