Re: (9.1) btree_gist support for searching on "not equals" - Mailing list pgsql-hackers

On 5/21/10 11:47 PM +0300, Jeff Davis wrote:
> It also allows you to enforce the constraint that only one tuple exists
> in a table by doing something like:
>
>    create table a
>    (
>      i int,
>      exclude using gist (i with<>),
>      unique (i)
>    );

FWIW, this is achievable a lot more easily:
CREATE UNIQUE INDEX "a_single_row" ON a ((1));


Regards,
Marko Tiikkaja