When a SQL expression uses multiple columns that have different policy expressions applied, the SQL expression is evaluated first and the result of the SQL expression is redacted if the user does not have the EXEMPT REDACTION POLICY privilege and if any of the policy expressions evaluates to TRUE.

Similarly, if redacted columns are present in the SELECT list on either side of set operators such as, UNION, UNION ALL, INTERSECT, MINUS, EXCEPT, and so on, the result of the SQL expression will be redacted if the user does not have the EXEMPT REDACTION POLICY privilege and if any of the policy expressions evaluates to TRUE.

For example, in a scenario where column 1 (c1) and column 2 (c2) have different policy expressions and the following queries are executed, the result will be redacted unless the policy expressions for both column 1 and column 2 evaluate to FALSE. This is further described in the table below.

SELECT SUM(c1, c2) sum_c1_c2 FROM t1;
SELECT c1 FROM t1 UNION SELECT c2 FROM t1;