set hive.multigroupby.singlereducer=true;

CREATE TABLE DEST1(key ARRAY<STRING>, value BIGINT) STORED AS TEXTFILE;
CREATE TABLE DEST2(key MAP<STRING, STRING>, value BIGINT) STORED AS TEXTFILE;

EXPLAIN
FROM SRC
INSERT OVERWRITE TABLE DEST1 SELECT ARRAY(SRC.key), COUNT(1) GROUP BY ARRAY(SRC.key) limit 10
INSERT OVERWRITE TABLE DEST2 SELECT MAP(SRC.key, SRC.value), COUNT(1) GROUP BY MAP(SRC.key, SRC.value) limit 10;

FROM SRC
INSERT OVERWRITE TABLE DEST1 SELECT ARRAY(SRC.key), COUNT(1) GROUP BY ARRAY(SRC.key) limit 10
INSERT OVERWRITE TABLE DEST2 SELECT MAP(SRC.key, SRC.value), COUNT(1) GROUP BY MAP(SRC.key, SRC.value) limit 10;

SELECT DEST1.* FROM DEST1 ORDER BY key[0] ASC, value ASC;
SELECT DEST2.* FROM DEST2 ORDER BY 1 ASC, value ASC;