Re: Add proper planner support for ORDER BY / DISTINCT aggregates

Gavin Flower <GavinFlower@archidevsys.co.nz> writes:
> On 2/07/21 8:39 pm, David Rowley wrote:
>> That's a good question. There was an argument in [1] that mentions
>> that there might be a group of people who rely on aggregation being
>> done in a certain order where they're not specifying an ORDER BY
>> clause in the aggregate.  If that group of people exists, then it's
>> possible they might be upset in the scenario that you describe.

> So I think that pg has no obligation to protect the sensibilities of 
> naive users in this case, especially at the expense of users that want 
> queries to complete as quickly as possible.  IMHO

I agree.  We've broken such expectations in the past and I don't
have much hesitation about breaking them again.

            regards, tom lane