12C New Feature : Move a Datafile Online (Doc ID 1566797.1)

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In this Document

Goal

Solution

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Applies to:

Oracle Database - Enterprise Edition - Version 12.1.0.1 and later
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Information in this document applies to any platform.

Goal

In this release, a data file can now be moved online while it is open and being accessed, even for data files in system tablespace.
Being able to move a data file online means that many maintenance operations, such as moving data to another storage device or moving databases into Oracle Automatic Storage Management (Oracle ASM), can be performed while users are accessing the system. This ensures that continuity of service and service-level agreements (SLA) on uptime can be met.

Solution

With Oracle 12C, you can now do the following operations while the datafile is online and being accessed:

1. Renaming an Online Data File
2. Relocating an Online Data File
3. Copying an Online Data File
4. Relocating an Online Data File and Overwriting an Existing File
5. Relocating an Online Data File to Oracle ASM

The following is an example of how each operation is done:

Renaming an Online Data File:
===============================

SQL> CREATE TABLESPACE test DATAFILE '<PATH>/<SID>/test.dbf' SIZE 50M
EXTENT MANAGEMENT LOCAL
SEGMENT SPACE MANAGEMENT AUTO;  2    3

Tablespace created.

SQL> select file_name, status, online_status from dba_data_files;

FILE_NAME
----------------------------------------------------------------------------------------------------
STATUS    ONLINE_
--------- -------
<PATH>/<SID>/system01.dbf
AVAILABLE SYSTEM

<PATH>/<SID>/sysaux01.dbf
AVAILABLE ONLINE

<PATH>/<SID>/undotbs01.dbf
AVAILABLE ONLINE

<PATH>/<SID>/users01.dbf
AVAILABLE ONLINE

<PATH>/<SID>/test.dbf
AVAILABLE ONLINE

SQL> ALTER DATABASE MOVE DATAFILE '<PATH>/<SID>/test.dbf'
TO '<PATH>/<SID>/test_renamed.dbf';

Database altered.

SQL> select file_name, status, online_status from dba_data_files where file_name='<PATH>/<SID>/test_renamed.dbf';

FILE_NAME
----------------------------------------------------------------------------------------------------
STATUS    ONLINE_
--------- -------
<PATH>/<SID>/test_renamed.dbf
AVAILABLE ONLINE

 
2. Relocating an Online Data File:
===================================

SQL> ALTER DATABASE MOVE DATAFILE '<PATH>/<SID>/test_renamed.dbf'
TO '<PATH>/test_renamed.dbf';
 
Database altered.

SQL> select file_name, status, online_status from dba_data_files where file_name='<PATH>/<SID>/test_renamed.dbf';

no rows selected

SQL> select file_name, status, online_status from dba_data_files;

FILE_NAME
----------------------------------------------------------------------------------------------------
STATUS    ONLINE_
--------- -------
<PATH>/<SID>/system01.dbf
AVAILABLE SYSTEM

<PATH>/<SID>/sysaux01.dbf
AVAILABLE ONLINE

<PATH>/<SID>/undotbs01.dbf
AVAILABLE ONLINE

<PATH>/<SID>/users01.dbf
AVAILABLE ONLINE

<PATH>/test_renamed.dbf
AVAILABLE ONLINE

 
3. Copying an Online Data File:
=================================

SQL> ALTER DATABASE MOVE DATAFILE '<PATH>/<SID>/test_renamed.dbf'
TO '<PATH>/test_renamed.dbf' keep;

Database altered.

SQL> select file_name, status, online_status from dba_data_files where file_name='<PATH>/<SID>/test_renamed.dbf';

no rows selected

SQL> select file_name, status, online_status from dba_data_files;

FILE_NAME
----------------------------------------------------------------------------------------------------
STATUS    ONLINE_
--------- -------
<PATH>/<SID>/system01.dbf
AVAILABLE SYSTEM

<PATH>/<SID>/sysaux01.dbf
AVAILABLE ONLINE

<PATH>/<SID>/undotbs01.dbf
AVAILABLE ONLINE

<PATH>/<SID>/users01.dbf
AVAILABLE ONLINE

<PATH>/test_renamed.dbf
AVAILABLE ONLINE

-- expect to see the entry:
-- <PATH>/<SID>/test_renamed.dbf
-- AVAILABLE ONLINE

-- However, when i try to move the datafile to the location <PATH>/<SID> i get the following error
-- which verifies that the datafile was indeed copied and kept available in the old location:

SQL> ALTER DATABASE MOVE DATAFILE '<PATH>/test_renamed.dbf'
TO '<PATH>/<SID>/test_renamed.dbf';   2
ALTER DATABASE MOVE DATAFILE '<PATH>/test_renamed.dbf'
*
ERROR at line 1:
ORA-01119: error in creating database file
'<PATH>/<SID>/test_renamed.dbf'
ORA-27038: created file already exists
Additional information: 1

 
4. Example of relocating an Online Data File and Overwriting an Existing File:
=====================================================================

SQL> ALTER DATABASE MOVE DATAFILE '<PATH>/test_renamed.dbf'
TO '<PATH>/<SID>/test_renamed.dbf' REUSE;

Database altered.

SQL> select file_name, status, online_status from dba_data_files where file_name='<PATH>/<SID>/test_renamed.dbf';

FILE_NAME
----------------------------------------------------------------------------------------------------
STATUS    ONLINE_
--------- -------
<PATH>/<SID>/test_renamed.dbf
AVAILABLE ONLINE


SQL> select file_name, status, online_status from dba_data_files;

FILE_NAME
----------------------------------------------------------------------------------------------------
STATUS    ONLINE_
--------- -------
<PATH>/<SID>/system01.dbf
AVAILABLE SYSTEM

<PATH>/<SID>/sysaux01.dbf
AVAILABLE ONLINE

<PATH>/<SID>/undotbs01.dbf
AVAILABLE ONLINE

<PATH>/<SID>/users01.dbf
AVAILABLE ONLINE

<PATH>/<SID>/test_renamed.dbf
AVAILABLE ONLINE

 
5. Relocate an Online Data File to Oracle ASM:
================================================

This example moves the data file user1.dbf from <PATH> directory to an Oracle ASM location.

ALTER DATABASE MOVE DATAFILE '<PATH>/user1.dbf' 
  TO '+dg_group1/user1.dbf';

This example moves the data file from one Oracle ASM location to another Oracle ASM location.

ALTER DATABASE MOVE DATAFILE +dg_group1/user1.dbf' 
  TO '+dg_group2/user1.dbf';

For more information about moving a datafile online, please refer to: http://docs.oracle.com/cd/E16655_01/server.121/e17636/dfiles.htm#ADMIN13837

12C New Feature : Move a Datafile Online (Doc ID 1566797.1)

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