RMAN Commands , 61 of 64

SWITCH

Syntax

Text description of the illustration switch.gif

Purpose

To specify that a datafile copy is now the current datafile, that is, the datafile pointed to by the control file. A switch is equivalent to using the ALTER DATABASE RENAME FILE statement: Oracle renames the files in the control file but does not actually rename them on the operating system. Note that this command deletes the records for the datafile copy from the recovery catalog and updates the control file records to status DELETED.

Restrictions and Usage Notes

Execute SWITCH within the braces of a VALIDATE command.
If the control file is a restored backup control file, then SWITCH adds the datafile to the control file if it is not there already. You can only add datafiles through SWITCH that were created after the backup control file was created.

Keywords and Parameters

DATAFILE datafileSpec

Specifies the datafile that you wish to rename. After the switch, the control file no longer views the specified file as current. For example, this command points the control file from tbs_1.f to cp1.f:

SWITCH DATAFILE '/oracle/dbs/tbs_1.f' TO DATAFILECOPY '/oracle/dbs/copies/cp1.f';

If you do not specify a TO option, then RMAN uses the filename specified on a prior SET NEWNAME command for this file number as the switch target.

TO DATAFILECOPY {'filename' | TAG = 'tag_name'}

Specifies the input copy file for the switch, that is, the datafile copy that you wish to rename. Specify the file by filename or tag. For example, the following command sets df2.copy as the filename for datafile 2:

SWITCH DATAFILE 2 TO DATAFILECOPY '/oracle/dbs/df2.copy';

Note that if you specify a tag and the tag is ambiguous, then RMAN uses the most current copy, that is, the one that requires the least recovery.

When the tag is not unique, then RMAN understands the tag to refer to the most recently created copy. Thus, the command:

SWITCH DATAFILE 3 TO DATAFILECOPY TAG mondayPMcopy;

switches datafile 3 to the most recently created Monday evening copy.

DATAFILE ALL

Specifies that all datafiles for which a SET NEWNAME FOR DATAFILE command has been issued in this job are switched to their new name.

Example

Switching Datafile Filenames After a Restore: Example

This example allocates one disk device and one tape device to allow RMAN to restore both from disk and tape.

RUN
{  
  ALLOCATE CHANNEL dev1 DEVICE TYPE DISK RATE 1000;  
  ALLOCATE CHANNEL dev2 DEVICE TYPE sbt;  
  SQL "ALTER TABLESPACE tbs_1 OFFLINE IMMEDIATE";  
  SET NEWNAME FOR DATAFILE '/disk7/oracle/tbs11.f' 
    TO '/disk9/oracle/tbs11.f';  
  RESTORE TABLESPACE tbs_1; 
  SWITCH DATAFILE ALL;  
  RECOVER TABLESPACE tbs_1;  
  SQL "ALTER TABLESPACE tbs_1 ONLINE";  
}