Renaming Files for RMAN Restore

       We usually need to duplicate our databases to test servers which have different disk layouts than production server. So we need to distribute the datafiles according to the disk space and directory structure of the new server. It becomes a time-consuming task if you’re dealing with hundreds of datafiles. Today I saw a PL/SQL script written by Bobby Durrett for renaming datafiles for RMAN restore. It produces required “set newname” commands which can be used by RMAN. That was a great idea and I decided to write my own version to satisfy my needs:


DECLARE
    CURSOR DF_CURSOR IS
        SELECT 'data' ft, FILE_ID, FILE_NAME,
        BYTES / (1024 * 1024 * 1024) fsize
        FROM dba_data_files
        union all
        SELECT 'temp' ft, FILE_ID, FILE_NAME,
        BYTES / (1024 * 1024 * 1024) fsize
        FROM dba_temp_files
        ORDER BY ft, file_id;
   TYPE array_number IS TABLE OF NUMBER;
   TYPE array_varchar2 IS TABLE OF VARCHAR2 (200);
   diskno      NUMBER;
   diskspace   array_number := array_number (
                                   1000,
                                   500,
                                   500,
                                   2500); -- Sizes in GB
   diskpath   array_varchar2 := array_varchar2 (
                                   '/u02/orauat1',
                                   '/u02/orauat2',
                                   '/u02/orauat3',
                                   '/u02/orauat4');
   prefix      VARCHAR2 (200) := '/ouinvrep/data'; -- will be added to diskpaths
   BEGIN
   FOR df IN DF_CURSOR
   LOOP
      FOR diskno IN 1 .. diskspace.COUNT
      LOOP
         IF (diskspace (diskno) > df.fsize)
         THEN
            DBMS_OUTPUT.put_line ( 'set newname for ' || df.ft || 'file '
               || df.FILE_ID || ' to  ''' || diskpath (diskno) || prefix
               || SUBSTR (df.FILE_NAME, INSTR (df.FILE_NAME, '/', -1))
               || ''';');
            diskspace (diskno) := diskspace (diskno) - df.fsize;
            EXIT;
         END IF;
      END LOOP;
   END LOOP;

END;

/

It’s very easy to edit this script. You just need to enter the disk partitions and available/free disk spaces (in gigabytes) on them (line 17 and 13). While entering the disk space in GBs, round the size down. You can set “prefix” (line 29) to empty string if you don’t want to use it. Here’s a sample output:

set newname for datafile 1 to  '/u02/orauat1/ouinvrep/data/system.1109.765271585';
set newname for datafile 2 to  '/u02/orauat1/ouinvrep/data/af_bu_data.339.765264843';

Note: Don't use this script directly on production environment without testing.