Purpose

This statement creates a new edition as a child of an existing edition. An edition makes it possible to have two or more versions of the same editionable objects in the database. When you create an edition, it immediately inherits all of the editionable objects of its parent edition. The following object types are editionable:

• Synonym

• View

• Function

• Procedure

• Package (specification and body)

• Type (specification and body)

• Library

• Trigger

An editionable object is an object of one of the above editionable object types in an editions-enabled schema. The ability to have multiple versions of these objects in the database greatly facilitates online application upgrades.

Every newly created or upgraded Oracle Database has one default edition named ORA$BASE, which serves as the parent of the first edition created with a CREATE EDITION statement. You can subsequently designate a user-defined edition as the database default edition using an ALTER DATABASE DEFAULT EDITION statement.

Prerequisites

To create an edition, you must have the CREATE ANY EDITION system privilege, granted either directly or through a role. To create an edition as a child of another edition, you must have the USE object privilege on the parent edition.

Syntax

create_edition::=

Description of the illustration create_edition.eps

Semantics

edition

Specify the name of the edition to be created. The name must satisfy the requirements listed in "Database Object Naming Rules".

To view the editions that have been created for the database, query the EDITION_NAME column of the DBA_OBJECTS or ALL_OBJECTS data dictionary view.

When you create an edition, the system automatically grants you the USE object privilege WITH GRANT OPTION on the edition you create.

AS CHILD OF Clause

If you use this clause, then the new edition is created as a child of parent_edition. If you omit this clause, then the new edition is created as a child of the leaf edition. At the time of its creation, the new edition inherits all editioned objects from its parent edition.

Restriction on Editions

An edition can have only one child edition. If you specify for parent_edition an edition that already has a child edition, then an error is returned.

Examples

The following very simple examples are intended to show the syntax for creating and working with an edition. For realistic examples of using editions refer to Oracle Database Development Guide.

In the following statements, the user HR is given the privileges needed to create and use an edition:

GRANT CREATE ANY EDITION, DROP ANY EDITION to HR;
Grant succeeded.

ALTER USER hr ENABLE EDITIONS;
User altered.

HR creates a new edition TEST_ED for testing purposes:

CREATE EDITION test_ed;

HR then creates an editioning view ed_view in the default edition ORA$BASE for testing purposes, first verifying that the current edition is the default edition:

SELECT SYS_CONTEXT('userenv', 'current_edition_name') FROM DUAL;
SYS_CONTEXT('USERENV','CURRENT_EDITION_NAME')
--------------------------------------------------------------------------------
ORA$BASE
1 row selected.

CREATE EDITIONING VIEW e_view AS
  SELECT last_name, first_name, email FROM employees;
View created.

DESCRIBE e_view
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 LAST_NAME                                 NOT NULL VARCHAR2(25)
 FIRST_NAME                                         VARCHAR2(20)
 EMAIL                                     NOT NULL VARCHAR2(25)

The view is then actualized in the TEST_ED edition when HR uses the TEST_ED edition and re-creates the view in a different form:

ALTER SESSION SET EDITION = TEST_ED;
Session altered.

CREATE OR REPLACE EDITIONING VIEW e_view AS
  SELECT last_name, first_name, email, salary FROM employees;

View created.

The view in the TEST_ED edition has an additional column:

DESCRIBE e_view
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 LAST_NAME                                 NOT NULL VARCHAR2(25)
 FIRST_NAME                                         VARCHAR2(20)
 EMAIL                                     NOT NULL VARCHAR2(25)
 SALARY                                             NUMBER(8,2)

The view in the ORA$BASE edition remains isolated from the test environment:

ALTER SESSION SET EDITION = ora$base;
Session altered.

DESCRIBE e_view;

 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 LAST_NAME                                 NOT NULL VARCHAR2(25)
 FIRST_NAME                                         VARCHAR2(20)
 EMAIL                                     NOT NULL VARCHAR2(25)

Even if the view is dropped in the test environment, it remains in the ORA$BASE edition:

ALTER SESSION SET EDITION = TEST_ED;
Session altered.

DROP VIEW e_view;
View dropped.

ALTER SESSION SET EDITION = ORA$BASE;
Session altered.

DESCRIBE e_view;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 LAST_NAME                                 NOT NULL VARCHAR2(25)
 FIRST_NAME                                         VARCHAR2(20)
 EMAIL                                     NOT NULL VARCHAR2(25)

When the testing of upgrade that necessitated the TEST_ED edition is complete, the edition can be dropped:

DROP EDITION TEST_ED;