On Sat, Oct 26, 2013 at 12:02 PM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
> Imo what it does looks sane - it adds parentheses whenever a child of a
> set operation is a set operation again to make sure the order in which
> the generated set operations are parsed/interpreted stays the same.
But UNION ALL is associative.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company