I find I am allowed to create an ordered-set aggregate with a non-empty direct argument list and no finisher function. Am I right in thinking that's kind of nonsensical, as nothing will ever look at the direct args?
Also, the syntax summary shows PARALLEL = { SAFE | RESTRICTED | UNSAFE } in the ordered-set syntax variant, since 9.6, though that variant accepts no combine/serial/deserial functions, and there's also a note saying "Partial (including parallel) aggregation is currently not supported for ordered-set aggregates." Does PARALLEL = { SAFE | RESTRICTED | UNSAFE } on an ordered-set aggregate affect anything? Regards, -Chap