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

On 10 April 2014 19:54, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Dean Rasheed <dean.a.rasheed@gmail.com> writes:
>> On 10 April 2014 19:04, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> What about names for the invertible-aggregate infrastructure?
>>> I'm tempted to prefix "inv" to all the existing names, but then
>>> "invsfunc" means the alternate forward function ... can we use
>>> "invifunc" for the inverse transition function?  Or maybe the
>>> prefix should be just "i".
>
>> Hmm, I'm not a fan of any of those names. Perhaps "win" as a prefix to
>> denote a sliding window? Or just "m" for "moving aggregate".
>
> Hmm ... "moving aggregate" is actually a pretty good name for this
> whole feature -- better than "invertible aggregate" anyway.  I can
> feel a global-search-and-replace coming on.
>
> So if we go with that terminology, perhaps these names for the
> new CREATE AGGREGATE parameters:
>
> initfunc        applies to plain aggregation, mutually exclusive with initcond
> msfunc          (or just mfunc?) forward transition for moving-agg mode
> mifunc          inverse transition for moving-agg mode
> mstype          state datatype for moving-agg mode
> msspace         space estimate for mstype
> mfinalfunc      final function for moving-agg mode
> minitfunc       "firsttrans" for moving-agg mode
> minitcond       mutually exclusive with minitfunc
>

Yeah, those work for me.

I think I prefer "mfunc" to "msfunc", but perhaps that's just my
natural aversion to the "ms" prefix :-)

Also, perhaps "minvfunc" rather than "mifunc" because "i" by itself
could mean "initial".

Regards,
Dean