Oracle UNION ALL/UNION/INTERSECT/MINUS

Operator Description UNION ALL Returns all the rows retrieved by the queries, including duplicate rows. UNION Returns all non-duplicate rows retrieved by the queries. INTERSECT Returns rows that are retrieved by both queries. MINUS Returns the remaining rows when the rows retrieved by the second query are subtracted from the rows retrieved by the first query.

Although the column names may be different, the number of columns and the column types returned by the queries must match.