On Thu, Oct 14, 2010 at 10:37 AM, Hitoshi Harada <umi.tanuki@gmail.com> wrote:
> I found PostgreSQL accepts UNION DISTINCT but documents don't mention it.
>
> http://www.postgresql.org/docs/9.0/static/sql-select.html#SQL-UNION
>
> select_statement UNION [ ALL ] select_statement
>
> UNION DISTINCT is nothing more than UNION itself, but gram.y
> definitely accept it and the SQL standard describes it as well. Should
> we add DISTINCT to docs?
+1, with due regard for the issue raised by Tom.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company