Peter Eisentraut <pete...@gmx.net> writes: > On fre, 2010-11-12 at 09:44 -0500, Tom Lane wrote: >> But I'm still not convinced that this feature is useful enough to >> justify the implementation effort. AFAICS there's nothing here that >> you couldn't get with some non-default operators on regular arrays,
> Unique constraints would behave differently for arrays and multisets. > But I suppose you could get something similar with exclusion constraints > nowadays. But not for primary keys. > Foreign keys also don't work easily with nondefault operators. > JOIN / USING doesn't work. > ORDER BY would work but look ugly. And such coding where you'd have to > remember the nondefault operator everywhere would also be error prone. Hmm. Those are perhaps good arguments --- but you can't get any of those behaviors unless multisets are distinct types. The implementation proposed upthread where they're arrays with a special typmod isn't going to support this. 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