Re: Sharing aggregate states between different aggregate functions

Heikki Linnakangas <hlinnaka@iki.fi> writes:
> On 07/28/2015 07:18 PM, Tom Lane wrote:
>> Heikki Linnakangas <hlinnaka@iki.fi> writes:
>>> BTW, we're also not checking if the transition or final functions are
>>> volatile. But that was the same before this patch too.

>> Up to now it hasn't mattered.

> Yes, it has. We combine identical aggregates even without this patch. 

Ah, right, how'd I forget about that?

> No-one's complained so far, and I can't think of a use case for a 
> volatile transition or final function, so maybe it's not worth worrying 
> about. Then again, checking for the volatility of those functions would 
> be easy too.

Given the lack of complaints, I tend to agree that it's not the province
of this patch to make a change in that policy.
        regards, tom lane