"David G. Johnston" <david.g.johns...@gmail.com> writes: > I'm more keen on the idea of having the system understand when an ORDER BY > is missing - that seems like what users are more likely to actually do.
That side of it could perhaps be useful, but not if it's an unintelligent analysis. If someone has a perfectly safe query written according to the old-school method: SELECT string_agg(...) FROM (SELECT ... ORDER BY ...) ss; they are not going to be too pleased with a nanny-ish warning (much less an error) saying that the aggregate's input ordering is underspecified. I also wonder whether we'd accept any ORDER BY whatsoever, or try to require one that produces a sufficiently-unique input ordering. regards, tom lane