2008/12/30 Jaime Casanova <jcasa...@systemguards.com.ec>: > On Mon, Dec 29, 2008 at 11:59 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: >> I wrote: >>> * Support creation of user-defined window functions. I think this is >>> a "must have" for 8.4 --- we are not in the habit of building >>> nonextensible basic features. It doesn't seem that hard either. >>> I think all we need do is to allow "WINDOW" as an attribute keyword >>> in CREATE FUNCTION. Does anyone have an objection or a better idea? >> >> What I had in mind when I wrote that was something like >> >> create [or replace] function mywindow(...) returns ... >> as 'mymodule, 'mywindow' >> language c >> window; >> > > i don't understand this window function stuff well yet, but AFAIU it > is like an aggregate function that shows grouped values without > grouping rows (ok, maybe a very laizy or novice definition) but if > that is correct or near correct maybe we need to follow the same > pattern: > > create function -- without any decoration > create aggregate maybe with a decoration of being window o create > window aggregate or something similar... >
I prefer "create window function" because it is semantically readable and window keyword is more similar to aggregate than immutable, or strict. And for drop/comment or so, I guess we don't need prepare window keyword. It's because window function is represented in pg_proc catalog only, whereas aggregate uses pg_proc and pg_aggregate. If there weren't window keyword in DROP FUNCTION, we won't be worried which function to be dropped? Regards, -- Hitoshi Harada -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
