Re: [PATCH] Negative Transition Aggregate Functions (WIP)

On Mar28, 2014, at 08:58 , Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com> wrote:
> On 27 March 2014 21:01, Florian Pflug <fgp(at)phlo(dot)org> wrote:
>> After re-reading the thread, I'd prefer to go with Dean's suggestion, i.e.
>> simply reporting the total number of invocations of the forward transition
>> functions, and the total number of invocations of the reverse transition
>> function, over reporting nothing. The labels of the two counts would simply
>> be "Forward Transitions" and "Reverse Transitions".
>>
>
> That should be "Inverse" not "Reverse" according to the terminology
> agreed upthread.

Ups, yeah.

> Personally, I'm not a big fan of that terminology because "forward"
> and "inverse" aren't natural antonyms. But actually I think that it's
> "forward" that is the wrong word to use, because they actually both
> move (different ends of) the frame forwards. The only alternatives I
> can think of are "direct" and "inverse", which are natural antonyms,
> but I don't want to hold up this patch bikeshedding over this. OTOH
> this is not the first time on this thread that someone has slipped
> into calling them "forward" and "reverse" transitions.

Head and tail come to mind. But having said that, I'd strongly prefer
not to start bikeschedding over this either. It's not user-visible
enough to fuss about it...

Also, for order-independent transfer functions, it really *is* an
inverse functions, in the sense that g(f(x,a),a) = x.

>>> Florian mentioned upthread that the docs hadn't been updated to
>>> reflect the latest changes, so I think they need a little attention.
>>
>> I'll see to updating the docs, and will post a final patch within the next
>> few days.

Attached are updated patches that include the EXPLAIN changes mentioned
above and updated docs.

best regards,
Florian Pflug