# needed to avoid the simplification of CAST(NULL) into NULL | |
set hive.cbo.rule.exclusion.regex=ReduceExpressionsRule\(Project\); | |
CREATE EXTERNAL TABLE t (a string, b string); | |
INSERT INTO t VALUES ('1000', 'b1'); | |
INSERT INTO t VALUES ('2000', 'b2'); | |
SELECT * FROM ( | |
SELECT | |
a, | |
b | |
FROM t | |
UNION ALL | |
SELECT | |
a, | |
CAST(NULL AS string) | |
FROM t) AS t2 | |
WHERE a = 1000; | |
EXPLAIN CBO | |
SELECT * FROM ( | |
SELECT | |
a, | |
b | |
FROM t | |
UNION ALL | |
SELECT | |
a, | |
CAST(NULL AS string) | |
FROM t) AS t2 | |
WHERE a = 1000; |