Now here a little script that will retrieve the size of database monthly. For execution of this script you will need to have select privilege on sys.v_$datafile view. Following query will retrieve results based on months, however you can easily tweak this query for creation_time column to get any type of extracts.

Script

select to_char(creation_time, 'YYYY Month') "Month",
    sum(bytes)/1024/1024 "Growth in MB"
    from sys.v_$datafile
    where creation_time > SYSDATE-365
    group by to_char(creation_time, 'YYYY Month');

Result

Month          Growth in MB
-------------- ------------
2010 December             2
2010 November            100

Description

It means that your session is trying to update an object that locked by another session. More specifically, your session has asked for a lock on the same object, but has specified the ‘nowait’ clause. The nowait clause, upon finding something locked, returns an error, rather than waiting for the lock to be released.

Solution

1. Run your script some other time, when database becomes idle or the object you want to update is lock free.
2. Kill the session that has the lock on the object.

For killing locked sessions following is the link to post that explain it in detail:

http://technoblogy.net/killing-locked-sessions-in-oracle/

Here are some examples, these can also be amended for user convenience:

SQL> SELECT floor(((date1-date2)*24*60*60)/3600)
  2         || ' HOURS ' ||
  3         floor((((date1-date2)*24*60*60) -
  4         floor(((date1-date2)*24*60*60)/3600)*3600)/60)
  5         || ' MINUTES ' ||
  6         round((((date1-date2)*24*60*60) -
  7         floor(((date1-date2)*24*60*60)/3600)*3600 -
  8         (floor((((date1-date2)*24*60*60) -
  9         floor(((date1-date2)*24*60*60)/3600)*3600)/60)*60) ))
 10         || ' SECS ' time_difference
 11    FROM dates;

TIME_DIFFERENCE
--------------------------------------------------------------------------------
24 HOURS 0 MINUTES 0 SECS
1 HOURS 0 MINUTES 0 SECS
0 HOURS 1 MINUTES 0 SECS

SQL> SELECT to_number( to_char(to_date('1','J') +
  2         (date1 - date2), 'J') - 1)  days,
  3         to_char(to_date('00:00:00','HH24:MI:SS') +
  4         (date1 - date2), 'HH24:MI:SS') time
  5   FROM dates;

      DAYS TIME
---------- --------
         1 00:00:00
         0 01:00:00
         0 00:01:00

SQL> select numtodsinterval(date1-date2,'day') time_difference from dates;

TIME_DIFFERENCE
----------------------------------------------------------------
+000000001 00:00:00.000000000
+000000000 01:00:00.000000000
+000000000 00:01:00.000000000

SQL> SELECT floor((date1-date2)*24)
  2         || ' HOURS ' ||
  3         mod(floor((date1-date2)*24*60),60)
  5         || ' MINUTES ' ||
  6         mod(floor((date1-date2)*24*60*60),60)
 10         || ' SECS ' time_difference
 11    FROM dates;

TIME_DIFFERENCE
--------------------------------------------------------------------------------
24 HOURS 0 MINUTES 0 SECS
1 HOURS 0 MINUTES 0 SECS
0 HOURS 1 MINUTES 0 SECS

You can view all the locked tables in schema by executing following query:

select table_name, stattype_locked

from dba_tab_statistics

where owner = ‘MBS’ and stattype_locked is not null;

Then how to unlock them, following query will help us to sort this issue:

select ‘exec DBMS_STATS.UNLOCK_TABLE_STATS (”’|| owner ||”’,”’|| table_name ||”’);’ from dba_tab_statistics where owner = ‘MBS’ and stattype_locked is not null;

or you can do that for every single table:

exec DBMS_STATS.UNLOCK_TABLE_STATS(‘owner’,'table name’);

"CREATE TABLE tableName AS". We cannot execute this statement in procedures because upon creation of procedure it would give syntax error.

We can implement this with the help of EXECUTE IMMEDIATE command and then dynamically create table.

create or replace procedure Proc1 as
begin
execute immediate ‘create table NewTable(column1 integer )’;
end ;

Some really easy steps to unlock an object or kill a session in oracle are as follows:

To view locked sessions in oracle:

select oracle_username,object_id,session_id from v$locked_object;

ORACLE_USERNAME OBJECT_ID SESSION_ID
—————————— ———- ———-
Lock_1 321876 130
Lock_2 320431 130
Lock_3 320429 130

Now checking the object that are locked, and that are not accessible:

select object_name from dba_objects where object_id = 321876;
OBJECT_NAME
——————————————————————————–
Table_1

Now you know which object is being locked and what is the object id whole session is to be killed.

First retrieve the serial# of object ID:

select sid,serial# from v$session where sid=130;
SID SERIAL#
———- ———-
130 8655

Now killing this session:

alter system kill session ’130,8655′;
System altered.

Now you can check by executing the first query again to see whether the locked session is still locked or not.

Syntax of creating a custom function:

CREATE [OR REPLACE] FUNCTION function_name
[ (parameter [,parameter]) ]
RETURN return_datatype
IS | AS
[declaration_section]
BEGIN
executable_section
[EXCEPTION
exception_section]
END [function_name];

Custom functions may have zero or more parameters in place. There are three types of parameters that can be defined in a custom function.

1. IN: This parameter can be called from a procedure or a function. The value of this parameter cannot be overwritten by procedure or function.
2. OUT: This parameter cannot be called from a procedure or function, but its value can be overwritten from them.
3. IN OUT: It has both the properties of above type. As it can be called from procedure and functions and also can be overwritten by them.

Some examples of creating and calling custom functions:

• Function without parameters.

Function with parameter.

Another workaround for this problem is by using the combination of LENGTH and TRANSLATE function:

LENGTH(TRANSLATE( mystr , ’0123456789A’ , ‘A’ ))

if above function returns null that means "mystr" contains only numbers , but if it is not null then the field is not numeric.