R1 and R2 must have the same number of columns, and the data type of the nth column of R1 must be compatible with the data type of the nth column of R2. Character-string values are compatible with datetime values.
The nth column of the result of UNION, UNION ALL, EXCEPT, or INTERSECT is derived from the nth columns of R1 and R2. The attributes of the result columns are determined using the rules for result columns. For more information see Rules for result data types.
If UNION, INTERSECT, or EXCEPT is specified, no column can be a LOB or DATALINK column.
(C) Copyright IBM Corporation 1992, 2006. All Rights Reserved.