Exploration of New Features of Oracle 12c – PART 1

Feature No.1 : Invisible Columns

 

Let us take example of a table as shown below with the following table columns defined.

1

In 12c you can add a new column and set it as “invisible”.

 

Sql statement: alter table VGCDBA.T_VGC_CAL_EXP add (test_column varchar2(20) invisible);

2

The sql statement using the “describe” command won’t show the invisible column:

3

Set it to “visible again”: alter table VGCDBA.T_VGC_CAL_EXP modify (test_column visible);

4

And after re-excuting the describe again, the column will be shown

5

 

Feature No.2 : Creating Multiple Indexes on the same column

 

Before 12cR1 you could not have the ability to create multiple indexes on the same column (or set of columns), now you can do that but it will invisible.

 

This can be beneficial to test application performance and different queries with affecting the current setup.

 

Example,

 

SQL> CREATE BITMAP INDEX VGCDBA.IX_TEST ON VGCDBA.T_VGC_CAL_EXP (TIME_UID)  INVISIBLE;

6

In the below table you can see two indexes on the same column

7

Feature No.3 : enable_ddl_logging

 

After enabling the ddl loggin, all “ddl statements” will be tracked and written in the alert log.

 

In my current 12cR1 database the parameter is set to false.

8

SQL> ALTER SYSTEM SET ENABLE_DDL_LOGGING=TRUE;

 

9

After performing multiple SQL DDL operations using the oracle user “vgcdba”

 

10

Location of the log can be found here: /oraclex/[db_name]/diag/rdbms/[db_name]/ [db_name]/log/ddl

 

The below “log.xml” file shows enteries for all DDL statement that has been executed:

 

11

For Further Refrence:

http://docs.oracle.com/database/121/REFRN/refrn10302.htm

http://www.oracle-base.com/articles/12c/automatic-diagnostics-repository-adr-enhancements-12cR1.php

 

Feature No.4 : executing SQL statements in RMAN

In 12c you can directly execute SQL & PL/SQL statements in an RMAN session, which gives extra flexibility for the DBA.

sql rman

 

i will post Part 2 for the new features soooooon 🙂

 

Thanks,

 

 

 

 

 

 

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