Can you take the RMAN backup of catalog database using the same catalog database ??

This is very interesting question.Can you take the backup of rman catalog database by connecting to the same database.The document suggest that the catalog database is same as any other database and the restore and recovery operations are also the same .So I thought of running a test to confirm.

1) Create tablespace to keep the recovery catalog schema

SQL> create tablespace rman datafile  '/u01/app/oracle/oradata/fsdb/rman01.dbs' size 10m autoextend on ;

Tablespace created.

2) Create the recovery catalog schema

SQL> CREATE USER rman IDENTIFIED BY XXXXX  DEFAULT TABLESPACE rman TEMPORARY TABLESPACE temp  QUOTA UNLIMITED ON rman;

User created.

SQL> GRANT CONNECT, RECOVERY_CATALOG_OWNER TO rman;

Grant succeeded.

3) Create catalog using rman command line

[oracle@localhost ~]$ rman catalog rman/password@fsdb

Recovery Manager: Release 11.2.0.1.0 - Production on Wed Aug 27 15:01:01 2014

Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.

connected to recovery catalog database

RMAN> create catalog;

recovery catalog created

4) Register the  same database to the catalog

[oracle@localhost ~]$ rman target / catalog rman/password@fsdb

Recovery Manager: Release 11.2.0.1.0 - Production on Wed Aug 27 15:02:59 2014

Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.

connected to target database: FSDB (DBID=1085674687)

connected to recovery catalog database

RMAN> register database;

database registered in recovery catalog

starting full resync of recovery catalog

full resync complete

5)Run rman L0 backup to check

RMAN> backup incremental level 0 database;

Starting backup at 27-AUG-14

allocated channel: ORA_DISK_1

channel ORA_DISK_1: SID=55 device type=DISK

channel ORA_DISK_1: starting incremental level 0 datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

.

.

.

.

Finished backup at 27-AUG-14

Starting Control File and SPFILE Autobackup at 27-AUG-14

piece handle=/u01/app/oracle/flash_recovery_area/FSDB/autobackup/2014_08_27/o1_mf_s_856710457_9zwl4vls_.bkp comment=NONE

Finished Control File and SPFILE Autobackup at 27-AUG-14

Seems like its working but still I feel that we should backup the  control file and spfile seperately even though the spfile and control file autobackup is on.