Re: Is this proper UNION behavior??

On Tue, 14 Nov 2000 13:35:14 +0000, Jules Bean wrote:

> On Mon, Nov 13, 2000 at 10:12:39PM -0500, Tom Lane wrote:
> > "Edward Q. Bridges" <ed.bridges@buzznik.com> writes:
> > > ebridges=> (select * from has_some_dupes)
> > > ebridges-> UNION
> > > ebridges-> (select * from has_some_dupes);
> >
> > [ produces the same result as "select * from has_some_dupes" ]
> >
> Of course, the real bug here is in SQL, namely that it allows
> duplicates in tables.
>

given the presence of SELECT DISTINCT and unique constraints, i
wouldn't consider it a bug in SQL.  probably better anyway to have
the flexibility of having duplicates in a table, while providing the
ability to constrain to unique tuples if necessary.