Description
See the test case below:
0: jdbc:hive2://localhost:10000/default> create table test (a int); 0: jdbc:hive2://localhost:10000/default> insert overwrite table test values (1); 0: jdbc:hive2://localhost:10000/default> set hive.optimize.union.remove=true; No rows affected (0.01 seconds) 0: jdbc:hive2://localhost:10000/default> set hive.mapred.supports.subdirectories=true; No rows affected (0.007 seconds) 0: jdbc:hive2://localhost:10000/default> SELECT COUNT(1) FROM test UNION ALL SELECT COUNT(1) FROM test; +----------+--+ | _u1._c0 | +----------+--+ +----------+--+
UNION ALL without COUNT function will work as expected:
0: jdbc:hive2://localhost:10000/default> select * from test UNION ALL SELECT * FROM test;
+--------+--+
| _u1.a |
+--------+--+
| 1 |
| 1 |
+--------+--+
Run the same query without setting hive.mapred.supports.subdirectories and hive.optimize.union.remove to true will give correct result:
0: jdbc:hive2://localhost:10000/default> set hive.optimize.union.remove; +-----------------------------------+--+ | set | +-----------------------------------+--+ | hive.optimize.union.remove=false | +-----------------------------------+--+ 0: jdbc:hive2://localhost:10000/default> SELECT COUNT(1) FROM test UNION ALL SELECT COUNT(1) FROM test; +----------+--+ | _u1._c0 | +----------+--+ | 1 | | 1 | +----------+--+
Attachments
Attachments
Issue Links
- is depended upon by
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HIVE-12840 stats optimize subqueries whenever possible in a union query
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- Open
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