Page History

...

The ALL and DISTINCT options specify whether duplicate rows should be returned. If none of these options are given, the default is ALL (all matching rows are returned). DISTINCT specifies removal of duplicate rows from the result set. Note, Hive supports SELECT DISTINCT * since 0.15 (HIVE-9194)

hive> SELECT col1, col2 FROM t1
    1 3
    1 3
    1 4
    2 5
hive> SELECT DISTINCT col1, col2 FROM t1
    1 3
    1 4
    2 5
hive> SELECT DISTINCT col1 FROM t1
    1
    2

...