pá 28. 2. 2020 v 16:30 odesílatel Pavel Stehule <pavel.steh...@gmail.com> napsal:
> > > čt 27. 2. 2020 v 15:37 odesílatel Pavel Stehule <pavel.steh...@gmail.com> > napsal: > >> >> Hi >> >> >>> 3) Any way to define CONSTANTs ? >>> We already talked a bit about this subject and also Gilles Darold >>> introduces it in this mailing-list topic but I'd like to insist on it. >>> I think it would be nice to have a way to say that a variable should not >>> be changed once defined. >>> Maybe it's hard to implement and can be implemented later, but I just >>> want to know if this concern is open. >>> >> >> I played little bit with it and I didn't find any nice solution, but >> maybe I found the solution. I had ideas about some variants, but almost all >> time I had a problem with parser's shifts because all potential keywords >> are not reserved. >> >> last variant, but maybe best is using keyword WITH >> >> So the syntax can looks like >> >> CREATE [ TEMP ] VARIABLE varname [ AS ] type [ NOT NULL ] [ DEFAULT >> expression ] [ WITH [ OPTIONS ] '(' ... ')' ] ] >> >> What do you think about this syntax? It doesn't need any new keyword, and >> it easy to enhance it. >> >> CREATE VARIABLE foo AS int DEFAULT 10 WITH OPTIONS ( CONSTANT); >> > > After some more thinking and because in other patch I support syntax > CREATE TRANSACTION VARIABLE ... I change my opinion and implemented support > for > syntax CREATE IMMUTABLE VARIABLE for define constants. > second try to fix pg_dump Regards Pavel > > See attached patch > > Regards > > Pavel > > >> >> ? >> >> Regards >> >> Pavel >> >> >>
schema-variables-20200229.patch.gz
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