On 3/7/21 11:37 AM, Pavel Stehule wrote: > ne 7. 3. 2021 v 11:28 odesÃlatel Vik Fearing <v...@postgresfriends.org> > napsal: > >> On 3/7/21 11:24 AM, Pavel Stehule wrote: >>>> >>>> And so you are now mandating an ORDER BY on every query and in every >>>> aggregate and/or window function. Users will not like that at all. I >>>> certainly shan't. >>>> >>> >>> The mandatory ORDER BY clause should be necessary for operations when the >>> result depends on the order. You need an order for calculation of median. >>> And you don't need to know an order for average. More if the result is >> one >>> number and is not possible to do a visual check of correctness (like >>> median). >> >> The syntax for median (percentile_cont(0.5)) already requires an order >> by clause. You are now requiring one on array_agg(). >> > > array_agg is discuttable, because PostgreSQL arrays are ordered set type. > But very common usage is using arrays instead and unordered sets (because > ANSI/SQL sets) are not supported. But anyway - for arrays I can do visual > check if it is ordered well or not.
If by "visual check" you mean "with my human eyeballs" then I would argue that that is always the case and we don't need nannying for other aggregates either. -- Vik Fearing
