set hive.fetch.task.conversion=more;

DESCRIBE FUNCTION elt;
DESCRIBE FUNCTION EXTENDED elt;

EXPLAIN
SELECT elt(2, 'abc', 'defg'),
       elt(3, 'aa', 'bb', 'cc', 'dd', 'ee', 'ff', 'gg'),
       elt('1', 'abc', 'defg'),
       elt(2, 'aa', CAST('2' AS TINYINT)),
       elt(2, 'aa', CAST('12345' AS SMALLINT)),
       elt(2, 'aa', CAST('123456789012' AS BIGINT)),
       elt(2, 'aa', CAST(1.25 AS FLOAT)),
       elt(2, 'aa', CAST(16.0 AS DOUBLE)),
       elt(null, 'abc', 'defg'),
       elt(0, 'abc', 'defg'),
       elt(3, 'abc', 'defg')
FROM src tablesample (1 rows);

SELECT elt(2, 'abc', 'defg'),
       elt(3, 'aa', 'bb', 'cc', 'dd', 'ee', 'ff', 'gg'),
       elt('1', 'abc', 'defg'),
       elt(2, 'aa', CAST('2' AS TINYINT)),
       elt(2, 'aa', CAST('12345' AS SMALLINT)),
       elt(2, 'aa', CAST('123456789012' AS BIGINT)),
       elt(2, 'aa', CAST(1.25 AS FLOAT)),
       elt(2, 'aa', CAST(16.0 AS DOUBLE)),
       elt(null, 'abc', 'defg'),
       elt(0, 'abc', 'defg'),
       elt(3, 'abc', 'defg')
FROM src tablesample (1 rows);