query: DESCRIBE FUNCTION abs
abs(x) - returns the absolute value of x
query: DESCRIBE FUNCTION acos
acos(x) - returns the arc cosine of x if -1<=x<=1 or NULL otherwise
query: DESCRIBE FUNCTION asin
asin(x) - returns the arc sine of x if -1<=x<=1 or NULL otherwise
query: DESCRIBE FUNCTION date_add
date_add(start_date, num_days) - Returns the date that is num_days after start_date.
query: DESCRIBE FUNCTION parse_url
parse_url(url, partToExtract[, key]) - extracts a part from a URL
query: DESCRIBE FUNCTION split
split(str, regex) - Splits str around occurances that match regex
query: DESCRIBE FUNCTION EXTENDED abs
abs(x) - returns the absolute value of x
Example:
  > SELECT abs(0) FROM src LIMIT 1;
  0
  > SELECT abs(-5) FROM src LIMIT 1;
  5
query: DESCRIBE FUNCTION EXTENDED acos
acos(x) - returns the arc cosine of x if -1<=x<=1 or NULL otherwise
Example:
  > SELECT acos(1) FROM src LIMIT 1;
  0
  > SELECT acos(2) FROM src LIMIT 1;
  NULL
query: DESCRIBE FUNCTION EXTENDED asin
asin(x) - returns the arc sine of x if -1<=x<=1 or NULL otherwise
Example:
  > SELECT asin(0) FROM src LIMIT 1;
  0
  > SELECT asin(2) FROM src LIMIT 1;
  NULL
query: DESCRIBE FUNCTION EXTENDED date_add
date_add(start_date, num_days) - Returns the date that is num_days after start_date.
start_date is a string in the format 'yyyy-MM-dd HH:mm:ss' or 'yyyy-MM-dd'. num_days is a number. The time part of start_date is ignored.
Example:
   > SELECT date_add('2009-30-07', 1) FROM src LIMIT 1;
  '2009-31-07'
query: DESCRIBE FUNCTION EXTENDED parse_url
parse_url(url, partToExtract[, key]) - extracts a part from a URL
Parts: HOST, PATH, QUERY, REF, PROTOCOL, AUTHORITY, FILE, USERINFO
key specifies which query to extract
Example:
  > SELECT parse_url('http://facebook.com/path/p1.php?query=1', 'HOST') FROM src LIMIT 1;
  'facebook.com'
  > SELECT parse_url('http://facebook.com/path/p1.php?query=1', 'QUERY') FROM src LIMIT 1;
  'query=1'
  > SELECT parse_url('http://facebook.com/path/p1.php?query=1', 'QUERY', 'query') FROM src LIMIT 1;
  '1'
query: DESCRIBE FUNCTION EXTENDED split
split(str, regex) - Splits str around occurances that match regex
Example:
  > SELECT split('oneAtwoBthreeC', '[ABC]') FROM src LIMIT 1;
  ["one", "two", "three"]