PREHOOK: query: -- Synonym. See udf_substr.q
DESCRIBE FUNCTION substring
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: -- Synonym. See udf_substr.q
DESCRIBE FUNCTION substring
POSTHOOK: type: DESCFUNCTION
substring(str, pos[, len]) - returns the substring of str that starts at pos and is of length len
PREHOOK: query: DESCRIBE FUNCTION EXTENDED substring
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION EXTENDED substring
POSTHOOK: type: DESCFUNCTION
substring(str, pos[, len]) - returns the substring of str that starts at pos and is of length len
Synonyms: substr
pos is a 1-based index. If pos<0 the starting position is determined by counting backwards from the end of str.
Example:
   > SELECT substring('Facebook', 5) FROM src LIMIT 1;
  'book'
  > SELECT substring('Facebook', -5) FROM src LIMIT 1;
  'ebook'
  > SELECT substring('Facebook', 5, 1) FROM src LIMIT 1;
  'b'