PREHOOK: query: DESCRIBE FUNCTION concat
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION concat
POSTHOOK: type: DESCFUNCTION
concat(str1, str2, ... strN) - returns the concatenation of str1, str2, ... strN
PREHOOK: query: DESCRIBE FUNCTION EXTENDED concat
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION EXTENDED concat
POSTHOOK: type: DESCFUNCTION
concat(str1, str2, ... strN) - returns the concatenation of str1, str2, ... strN
Returns NULL if any argument is NULL.
Example:
  > SELECT concat('abc', 'def') FROM src LIMIT 1;
  'abcdef'
PREHOOK: query: SELECT
  concat('a', 'b'),
  concat('a', 'b', 'c'),
  concat('a', null, 'c'),
  concat(null),
  concat('a'),
  concat(null, 1, 2),
  concat(1, 2, 3, 'a'),
  concat(1, 2),
  concat(1),
  concat('1234', 'abc', 'extra argument')
FROM src LIMIT 1
PREHOOK: type: QUERY
PREHOOK: Input: default@src
PREHOOK: Output: file:/data/users/pyang/trunk/VENDOR.hive/trunk/build/ql/tmp/1314227124/10000
POSTHOOK: query: SELECT
  concat('a', 'b'),
  concat('a', 'b', 'c'),
  concat('a', null, 'c'),
  concat(null),
  concat('a'),
  concat(null, 1, 2),
  concat(1, 2, 3, 'a'),
  concat(1, 2),
  concat(1),
  concat('1234', 'abc', 'extra argument')
FROM src LIMIT 1
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
POSTHOOK: Output: file:/data/users/pyang/trunk/VENDOR.hive/trunk/build/ql/tmp/1314227124/10000
ab	abc	NULL	NULL	a	NULL	123a	12	1	1234abcextra argument