Re: PATCH: decreasing memory needlessly consumed by array_agg

On Tue, 2015-01-20 at 23:37 +0100, Tomas Vondra wrote:
> Tom's message where he points that out is here:
> http://www.postgresql.org/message-id/20707.1396372100@sss.pgh.pa.us

That message also says:

"I think a patch that stood a chance of getting committed would need to
detect whether the aggregate was being called in simple or grouped
contexts, and apply different behaviors in the two cases."

I take that as an objection to any patch which does not distinguish
between the grouped and ungrouped aggregate cases, which includes your
patch.

I don't agree with that objection (or perhaps I don't understand it);
but given the strong words above, I need to get some kind of response
before I can consider committing your patch.

> I generally agree that having two API 'facets' with different behavior
> is slightly awkward and assymetric, but I wouldn't call that ugly.

Right, your words are more precise (and polite). My apologies.

> I
> actually modified both APIs initially, but I think Ali is right that not
> breaking the existing API (and keeping the original behavior in that
> case) is better. We can break it any time we want in the future, but
> it's impossible to "unbreak it" ;-)

We can't break the old API, and I'm not suggesting that we do. I was
hoping to find some alternative.

Regards,
Jeff Davis