Complex view table 
A view table (see
CREATE VIEW statement) is a complex view table if it satisfies one of the following conditions:- The definition of the view table contains DISTINCT or GROUP BY or HAVING.
- The CREATE VIEW statement contains EXCEPT, INTERSECT, or UNION.
- The
SEARCH condition in the
QUERY expression of the CREATE VIEW statement contains a
subquery.
The CREATE VIEW statement contains an outer join, that is an OUTER JOIN indicator in a
JOIN predicate of the SEARCH condition.