2008/12/29 Tom Lane <t...@sss.pgh.pa.us>: > 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; >
+1 regards Pavel Stehule > but on reflection there seems to be a case also for > > create [or replace] window function mywindow(...) returns ... > as 'mymodule, 'mywindow' > language c; > > The main argument in favor of the latter is that window-ness will need > to be a fixed property of a function that you can't change except by > dropping and recreating it, because any existing views calling the > function will have its window-ness embedded in them in the form of > whether they use a FuncExpr or WindowFunc node to call it. So it > doesn't feel quite like an optional attribute. > > However, if we do that then for consistency we'd have to invent > DROP WINDOW FUNCTION, ALTER WINDOW FUNCTION, RENAME WINDOW FUNCTION, > COMMENT ON WINDOW FUNCTION, yadda yadda, and insist that you refer > to a function properly (with or without WINDOW) in each one of these > commands. Which would be a real PITA to implement and document, > and I can't see that it's doing anything much for users either. > > So I'm still leaning to the first way. Comments? > > regards, tom lane > > -- > Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-hackers > -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
