-- from_json
SELECT from_json('{"a":1, "b":0.8}', 'a INT, b DOUBLE');
+---------------------------+
|from_json({"a":1, "b":0.8})|
+---------------------------+
|                   [1, 0.8]|
+---------------------------+

SELECT from_json('{"time":"26/08/2015"}', 'time Timestamp', map('timestampFormat', 'dd/MM/yyyy'));
+--------------------------------+
|from_json({"time":"26/08/2015"})|
+--------------------------------+
|            [2015-08-26 00:00...|
+--------------------------------+

-- get_json_object
SELECT get_json_object('{"a":"b"}', '$.a');
+-------------------------------+
|get_json_object({"a":"b"}, $.a)|
+-------------------------------+
|                              b|
+-------------------------------+

-- json_tuple
SELECT json_tuple('{"a":1, "b":2}', 'a', 'b');
+---+---+
| c0| c1|
+---+---+
|  1|  2|
+---+---+

-- schema_of_json
SELECT schema_of_json('[{"col":0}]');
+---------------------------+
|schema_of_json([{"col":0}])|
+---------------------------+
|       array<struct<col:...|
+---------------------------+

SELECT schema_of_json('[{"col":01}]', map('allowNumericLeadingZeros', 'true'));
+----------------------------+
|schema_of_json([{"col":01}])|
+----------------------------+
|        array<struct<col:...|
+----------------------------+

-- to_json
SELECT to_json(named_struct('a', 1, 'b', 2));
+---------------------------------+
|to_json(named_struct(a, 1, b, 2))|
+---------------------------------+
|                    {"a":1,"b":2}|
+---------------------------------+

SELECT to_json(named_struct('time', to_timestamp('2015-08-26', 'yyyy-MM-dd')), map('timestampFormat', 'dd/MM/yyyy'));
+---------------------------------------------------------------------+
|to_json(named_struct(time, to_timestamp('2015-08-26', 'yyyy-MM-dd')))|
+---------------------------------------------------------------------+
|                                                 {"time":"26/08/20...|
+---------------------------------------------------------------------+

SELECT to_json(array(named_struct('a', 1, 'b', 2)));
+----------------------------------------+
|to_json(array(named_struct(a, 1, b, 2)))|
+----------------------------------------+
|                         [{"a":1,"b":2}]|
+----------------------------------------+

SELECT to_json(map('a', named_struct('b', 1)));
+-----------------------------------+
|to_json(map(a, named_struct(b, 1)))|
+-----------------------------------+
|                      {"a":{"b":1}}|
+-----------------------------------+

SELECT to_json(map(named_struct('a', 1),named_struct('b', 2)));
+----------------------------------------------------+
|to_json(map(named_struct(a, 1), named_struct(b, 2)))|
+----------------------------------------------------+
|                                     {"[1]":{"b":2}}|
+----------------------------------------------------+

SELECT to_json(map('a', 1));
+------------------+
|to_json(map(a, 1))|
+------------------+
|           {"a":1}|
+------------------+

SELECT to_json(array((map('a', 1))));
+-------------------------+
|to_json(array(map(a, 1)))|
+-------------------------+
|                [{"a":1}]|
+-------------------------+