query: -- If the argument is a string, hex should return a string containing two hex
-- digits for every character in the input.
SELECT
  hex('Facebook'),
  hex('\0'),
  hex('qwertyuiopasdfghjkl')
FROM src LIMIT 1
Input: default/src
Output: file:/data/users/emil/hive1/hive1/build/ql/tmp/375294624/10000
46616365626F6F6B	00	71776572747975696F706173646667686A6B6C
query: -- If the argument is a number, hex should convert it to hexadecimal.
SELECT
  hex(1),
  hex(0),
  hex(4207849477)
FROM src LIMIT 1
Input: default/src
Output: file:/data/users/emil/hive1/hive1/build/ql/tmp/1068245471/10000
1	0	FACEB005
query: -- Negative numbers should be treated as two's complement (64 bit).
SELECT hex(-5) FROM src LIMIT 1
Input: default/src
Output: file:/data/users/emil/hive1/hive1/build/ql/tmp/1738127711/10000
FFFFFFFFFFFFFFFB