RPAD(): This function is used to left pad the the given string with specified character or string.

SQL > SELECT RPAD('BILL ' , 12 , 'CLINTON') FROM DUAL;

RPAD('BILL',
------------
BILL CLINTON

LTRIM(): This function removes specified string from the given string if it is there to the left of given string.

SQL > SELECT LTRIM('GEORGE BUSH', 'GEORGE') FROM DUAL;

LTRIM
-----
 BUSH

RTRIM(): This function removes specified string from the given string if it is there to the right of given string.

SQL > SELECT RTRIM('TONY BLAIR', 'AIR') FROM DUAL;

RTRIM('
-------
TONY BL

ASCII(): Displays equivalent ASCII value of a character.
SQL > SELECT ASCII('A') FROM DUAL;

ASCII('A')
----------
        65

SQL >SELECT TRANSLATE('JOHN','H','N') FROM DUAL;

TRAN
----
JONN

OTHER FUNCTIONS:

Note: Arguments to the below given functions are in terms of radians

COS(x): It returns the Cosine of x.
SQL> SELECT COS(0) FROM DUAL;
    COS(0)
----------
         1
COSH(x) : It returns hyperbolic cosine of x.

SQL> SELECT COSH(0) FROM DUAL;

   COSH(0)
----------
         1

SIN(x) : It returns sine of x.

SQL> SELECT SIN(0) FROM DUAL;

    SIN(0)
----------
         0

SINH(x): It returns hyperbolic sine of x.

SQL> SELECT SINH(0) FROM DUAL;

   SINH(0)
----------
         0

TAN(x): It returns tangent of x.

SQL> SELECT TAN(0) FROM DUAL;

    TAN(0)
----------
         0

TANH(x): It returns hyperbolic tangent of x.
SQL> SELECT TANH(0) FROM DUAL;

   TANH(0)
----------
         0

DATE FUNCTIONS:
          
 ADD_MONTHS(date, n) : Adds n months to the specified date .

  SQL> SELECT  ADD_MONTHS('1-JAN-05',5) FROM DUAL;

  ADD_MONTHS
  ------------------
  01-JUN-05

LAST_DAY(date): Gives last date of the specified month (date).

SQL> SELECT LAST_DAY('1-JAN-05') FROM DUAL;

LAST_DAY(
---------
31-JAN-05

MONTHS_BETWEEN(date1, date2): It gives difference between the two dates date1, date2 in months.

SQL>  SELECT MONTHS_BETWEEN('31-DEC-05','1-JAN-05') FROM DUAL

MONTHS_BETWEEN('31-DEC-05','1-JAN-05')
--------------------------------------
                            11.9677419

SQL>  SELECT MONTHS_BETWEEN('31-JUL-05','1-JUL-05') FROM DUAL

MONTHS_BETWEEN('31-JUL-05','1-JUL-05')
--------------------------------------
                            .967741935