CREATE EXTERNAL TABLE t (a string, b string); | |
INSERT INTO t VALUES ('1000', 'b1'); | |
INSERT INTO t VALUES ('1001', 'b1'); | |
INSERT INTO t VALUES ('1002', 'b1'); | |
INSERT INTO t VALUES ('2000', 'b2'); | |
SELECT * FROM ( | |
SELECT | |
a, | |
b | |
FROM t | |
UNION ALL | |
SELECT | |
a, | |
b | |
FROM t | |
WHERE a = '1001' | |
UNION ALL | |
SELECT | |
a, | |
b | |
FROM t | |
WHERE a = '1002') AS t2 | |
WHERE a = '1000'; | |
EXPLAIN CBO | |
SELECT * FROM ( | |
SELECT | |
a, | |
b | |
FROM t | |
UNION ALL | |
SELECT | |
a, | |
b | |
FROM t | |
WHERE a = '1001' | |
UNION ALL | |
SELECT | |
a, | |
b | |
FROM t | |
WHERE a = '1002') AS t2 | |
WHERE a = '1000'; |