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

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: [PATCH] Negative Transition Aggregate Functions (WIP)
Дата
Msg-id 31823.1397237143@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: [PATCH] Negative Transition Aggregate Functions (WIP)  (Dean Rasheed <dean.a.rasheed@gmail.com>)
Список pgsql-hackers
Dean Rasheed <dean.a.rasheed@gmail.com> writes:
> On 10 April 2014 19:54, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> 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 :-)

Meh.  We've got mstype, and I don't think leaving out the "s" there
feels right.

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

Good point.  So with initfuncs out of the picture, we have
new CREATE AGGREGATE parameter names

msfunc        forward transition for moving-agg mode
minvfunc    inverse transition for moving-agg mode
mfinalfunc    final function for moving-agg mode
mstype        state datatype for moving-agg mode
msspace        space estimate for mstype
minitcond    initial state value for moving-agg mode

and new pg_aggregate columns

aggmtransfn       | regproc  | not null
aggminvtransfn    | regproc  | not null
aggmfinalfn       | regproc  | not null
aggmtranstype     | oid      | not null
aggmtransspace    | integer  | not null
aggminitval       | text     | 

It's a bit unfortunate that the catalog column names aren't quite on
the same page as CREATE AGGREGATE, but it doesn't seem like a good
idea to try to fix that now.
        regards, tom lane



В списке pgsql-hackers по дате отправления:

Предыдущее
От: Florian Pflug
Дата:
Сообщение: Re: [PATCH] Negative Transition Aggregate Functions (WIP)
Следующее
От: Tom Lane
Дата:
Сообщение: Re: [PATCH] Negative Transition Aggregate Functions (WIP)