Gavin Sherry <swm@alcove.com.au> writes:
> On Fri, 19 Jan 2007, Tom Lane wrote:
>> Er, what primary key would that be exactly? And even if you had a key,
>> I wouldn't call joining on it trivial; I'd call it expensive ...
> I should have used slightly different language. What I meant to say was,
> both sets are primarily sorted by saledate so they can be merged back
> together. This is why I said it was trivial.
Ah, my misunderstanding. Then isn't this basically isomorphic to what
I was thinking of, ie, somewhat-smarter Aggref nodes attached to the
existing GroupAggregate plan node?
regards, tom lane