>> So the question I'm now wondering about is whether this consideration >> makes variadic aggregates a bad idea all around, even if we don't have >> any built-in ones. Is the risk of user confusion (in the use of their >> own aggregate) sufficient reason to reject such a feature?
> can be this issue solved by syntax? > In September commitfest is patch for "WITHIN GROUP" where ORDER BY clause > is safety separated from parameters.
That might not be the ugliest syntax the SQL committee ever invented, but it's right up there. I don't want to go that way, especially not when the existing precedent for the same feature with regular functions doesn't use any weird special syntax.
It is maybe not nice, but it is long years supported by almost all SQL servers.
When I talked with Atri, he mentioned, so variadic aggregates are supported there too.
Regards
Pavel
On further reflection, what the "policy" was actually about was not that we should forbid users from creating potentially-confusing aggregates themselves, but only that we'd avoid having any *built in* aggregates with this hazard. So maybe I'm overthinking this, and the correct reading is just that we should have a policy against built-in variadic aggregates.
can be this potentially strange situation identified? - and some warning can be raised.
