Oracle Database 12c R1 New Features - Invisible columns

Oracle Database 12c R1 New Features - Invisible columns

In Oracle Database 12c R1, you can now have an invisible column in a table. When a column is defined as invisible, the column does not appear in generic queries, unless the column is explicitly referred to in the SQL statement or condition, or DESCRIBED in the table definition. You can add or modify a column to be invisible and vice versa.

You must explicitly refer to the invisible column name with the INSERT statement to insert the database into invisible columns. A virtual column or partition column can be defined as invisible too. However, temporary tables, external tables and cluster tables won’t support invisible columns.


Example:

Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing opt
ions

SQL> CREATE TABLE EMP_RECORDS
  2  (EMP_NO number (5),
  3  EMP_NAME varchar2 (30),
  4  EMP_SAL number (6) INVISIBLE)
  5  /

Table created.

SQL> desc EMP_RECORDS;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------

 EMP_NO                                             NUMBER(5)
 EMP_NAME                                       VARCHAR2(30)


SQL> alter table emp_records
  2  modify (emp_sal visible)
  3  /

Table altered.

SQL> desc emp_records
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------

 EMP_NO                                             NUMBER(5)
 EMP_NAME                                        VARCHAR2(30)
 EMP_SAL                                            NUMBER(6)

Related:

Installing Oracle Database 12c R1 (12.1.0.1.0)

Oracle Database 12c R1 New Features - Multiple Indexes on the same column or set of columns

Installation of Oracle Database 12c R1 (12.1.0.1.0)

Installation of Oracle Database 12c R1 (12.1.0.1.0)

Run setup.exe from installer directory (This is on windows, similarly invoke installer on Linux environment)

Oracle Database 12c Release 1 Installer - Installing Database

Step 1: Configure security updates

Enter My Oracle Support Username / Password to receive security updates via My Oracle Support (optional)

Step 2: Download Software updates

Enter My Oracle Support credentials to download software updates for this installation (optional)

Step 3: Select Installation Option

i)  Create and configure a database (Select this option)
ii) Install database software only
iii)Upgrade an existing database 

Step 4: System Class

i) Desktop class (Choose this option)
ii)Server class

Step 5: Specify Oracle Home User

i) Use Existing Windows User
ii) Create New Windows USer 
iii)Use Windows Built-in account (Option chosen - No need to specify username or password)


Step 6: Typical Install Configuration

Enter Administrative password: Simple4u

Step 7: Prerequisite checks

Step 8: Summary

Step 9: Install

At the end of installation, you will see on screen 

The installation of Oracle Database was successful.

Your database configuration files have been installed in C:\app\ while other components selected for installation have been installed in C:\app\product\12.1.0\dbhome_1.  Be cautious not to accidentally delete these configuration files.


SQL> select instance_name, status, version, database_status from v$instance;

INSTANCE_NAME    STATUS       VERSION           DATABASE_STATUS
---------------- ------------ ----------------- -----------------

newdb12c         OPEN         12.1.0.1.0        ACTIVE


Deinstalling Oracle Database 12c:

Go to $DB_HOME/deinstall and execute deinstall script.

For eg:

C:\app\db12c\product\12.1.0\dbhome_1\deinstall>deinstall


Related:

Oracle Database 12c R1 New Features - Invisible columns

Oracle Database 12c R1 New Features - Multiple Indexes on the same column or set of columns