Sunday, 19 April 2009

11 G New Features

In this article we will cover new features of 11 G

1) Case senstive Passwords : In 11G oracle password are case senstive ,but this feature can be changed by altering the parameter 

   ALTER SYSTEM SET SEC_CASE_SENSITIVE_LOGON = FALSE;
   
2) Invisible indexes :In 11G we can make index invisible .Once we make index invisible it will be ignored by Optimiser 

CREATE INDEX index_name ON table_name(column_name) INVISIBLE;

ALTER INDEX index_name INVISIBLE;

Invisible index is useful in cases where you want to see the impact of dropping the indexes.

3)Read only Tables : In 11G we can create read only tables

ALTER TABLE table_name READ ONLY;

In previous versions to make a table read only we have to restrict by giving select access.

We can again make it availaible for writing by 

ALTER TABLE table_name READ WRITE;

4) PL/SQL Function Result Cache 

PL/SQL Function result cache provides a nice way to enhance the performance of Oracle functions by storing 
the results of specific input parameter combination of function calls in SGA .


This will be particularly useful in cases where sql function is being called in SQL query or PL/SQL loop.


CREATE OR REPLACE FUNCTION test_cache (p_in IN NUMBER)
  RETURN NUMBER
  RESULT_CACHE
AS

5)DDL With the WAIT Option 

In prior 11G if you try to alter a table which is undergoing some DML operation you will get the error 
"ORA-00054: resource busy" 

ALTER SESSION SET ddl_lock_timeout=20;

DDL_LOCK_TIMEOUT parameter tells the number of seconds a DDL coomand should wait for Locks to become available.

We will discuss more features of 11 G in coming articles.

If  you want to have further details on 11 G new features please mail us at support@itnirvanas.com


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