st 18. 11. 2020 v 21:21 odesílatel Pavel Stehule <pavel.steh...@gmail.com> napsal:
> > > st 18. 11. 2020 v 6:58 odesílatel Pavel Stehule <pavel.steh...@gmail.com> > napsal: > >> >> >> út 17. 11. 2020 v 21:45 odesílatel Chapman Flack <c...@anastigmatix.net> >> napsal: >> >>> On 11/17/20 15:18, Jack Christensen wrote: >>> >> CREATE OR REPLACE FUNCTION very_long_name(par1 int) >>> >> RETURNS int AS $$ >>> >> #routine_label lnm >>> >> BEGIN >>> >> RAISE NOTICE '%', lnm.par1; >>> >>> Could that be somehow shoehorned into the existing ALIAS syntax, maybe as >>> >>> DECLARE >>> lnm ALIAS FOR ALL very_long_name.*; >>> >>> or something? >>> >> >> I thought about it - but I don't think so this syntax is correct - in >> your case it should be >> >> lnm.* ALIAS FOR ALL very_long_name.*; >> >> but it looks a little bit scary in ADA based language. >> >> Maybe >> >> DECLARE lnm LABEL ALIAS FOR very_long_name; >> >> or >> >> DECLARE lnm ALIAS FOR LABEL very_long_name; >> >> I think so implementation should not be hard. But there are advantages, >> disadvantages - 1. label aliasing increases the complexity of variable >> searching (instead comparing string with name of namespace, you should >> compare list of names). Probably not too much. 2. The syntax is a little >> bit harder than #option. Implementation based on #option can just rename >> top namespace, so there is not any overhead, and parsing #option syntax is >> pretty simple (and the syntax is shorter). So from implementation reasons I >> prefer #option based syntax. There is clear zero impact on performance. >> >> Regards >> > > I checked code - and I have to change my opinion - the current > implementation of namespaces in plpgsql doesn't allow renaming or realising > labels elegantly. The design has low memory requirements but it is not > flexible. I wrote a proof concept patch, and I had to hack the nsitem > little bit. > > postgres=# create or replace function bubu(a int, b int) > returns void as $$ > #routine_label b > maybe a better name for this option can be "routine_alias". > begin > raise notice '% %', b.a, b.b; > end; > $$ language plpgsql; > CREATE FUNCTION > postgres=# select bubu(10,20); > NOTICE: 10 20 > ┌──────┐ > │ bubu │ > ╞══════╡ > │ │ > └──────┘ > (1 row) > > > >> Pavel >> >> >>> >>> (And would it be cool if Table C.1 [1] had some sort of javascript-y >>> filtering on reservedness categories, for just such kinds of >>> bikeshedding?) >>> >>> Regards, >>> -Chap >>> >>> >>> [1] >>> https://www.postgresql.org/docs/13/sql-keywords-appendix.html#KEYWORDS-TABLE >>> >>
