On Tue, Sep 24, 2013 at 5:58 AM, Bernd Helmle <maili...@oopsware.de> wrote: > --On 13. September 2013 20:17:19 -0400 Robert Haas <robertmh...@gmail.com> > wrote: >> You're missing the point. Peter wasn't worried that your patch throws >> an error; he's concerned about the fact that it doesn't. >> >> In PostgreSQL, you can only create the following view because test1 >> has a primary key over column a: >> >> => create table test1 (a int constraint pk primary key, b text); >> => create view test2 as select a, b from test1 group by a; >> => alter table test1 drop constraint pk; >> >> The reason that, if the primary key weren't there, it would be >> ambiguous which row should be returned as among multiple values where >> a is equal and b is not. If you can disable the constraint, then you >> can create precisely that problem. > > Hmm not sure i understand this argument either: this patch doesn't allow > disabling a primary key. It only supports FKs and CHECK constraints > explicitly.
Well, that is certainly one way of skating around the specific concern Peter raised. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
