PREHOOK: query: DESCRIBE FUNCTION unhex
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION unhex
POSTHOOK: type: DESCFUNCTION
unhex(str) - Converts hexadecimal argument to string
PREHOOK: query: DESCRIBE FUNCTION EXTENDED unhex
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION EXTENDED unhex
POSTHOOK: type: DESCFUNCTION
unhex(str) - Converts hexadecimal argument to string
Performs the inverse operation of HEX(str). That is, it interprets
each pair of hexadecimal digits in the argument as a number and
converts it to the character represented by the number. The
resulting characters are returned as a binary string.

Example:
> SELECT UNHEX('4D7953514C') from src limit 1;
'MySQL'
> SELECT UNHEX(HEX('string')) from src limit 1;
'string'
> SELECT HEX(UNHEX('1267')) from src limit 1;
'1267'

The characters in the argument string must be legal hexadecimal
digits: '0' .. '9', 'A' .. 'F', 'a' .. 'f'. If UNHEX() encounters
any nonhexadecimal digits in the argument, it returns NULL. Also,
if there are an odd number of characters a leading 0 is appended.
PREHOOK: query: -- Good inputs

SELECT
  unhex('4D7953514C'),
  unhex('31323637'),
  unhex('61'),
  unhex('2D34'),
  unhex('')
FROM src limit 1
PREHOOK: type: QUERY
PREHOOK: Input: default@src
PREHOOK: Output: file:/Users/carl/Projects/hd9/hive-trunk/build/ql/tmp/1211131149/10000
POSTHOOK: query: -- Good inputs

SELECT
  unhex('4D7953514C'),
  unhex('31323637'),
  unhex('61'),
  unhex('2D34'),
  unhex('')
FROM src limit 1
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
POSTHOOK: Output: file:/Users/carl/Projects/hd9/hive-trunk/build/ql/tmp/1211131149/10000
MySQL	1267	a	-4	
PREHOOK: query: -- Bad inputs
SELECT
  unhex('MySQL'),
  unhex('G123'),
  unhex('\0')
FROM src limit 1
PREHOOK: type: QUERY
PREHOOK: Input: default@src
PREHOOK: Output: file:/Users/carl/Projects/hd9/hive-trunk/build/ql/tmp/1374300168/10000
POSTHOOK: query: -- Bad inputs
SELECT
  unhex('MySQL'),
  unhex('G123'),
  unhex('\0')
FROM src limit 1
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
POSTHOOK: Output: file:/Users/carl/Projects/hd9/hive-trunk/build/ql/tmp/1374300168/10000
NULL	NULL	NULL