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‘;
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