Introduction to the difference between catalog and Nocatalog in Rman

Nocatalog Way is to use control file as a catalog, each backup to the controlling files to write a lot of backup information, control files will have more and more backup information. For catalog, you must first create a directory backup database and establish a recovery directory.

Catlog to establish a recovery directory:

1. Table space required to create catalog

Sql>create tablespace rman_ts datafile '/u01/oracle/oradata/ora10g/rmants.dbf ' size 20M;

2. Create an Rman user and authorize

Sql>create user Rman identified by Rman default Tablespace rman_ts quota unlimited on rman_ts;
Sql>grant Recovery_catalog_owner to Rman; (Grant connect to Rman)

To view the permissions that a role has:

SELECT * from Dba_sys_privs where grantee= ' Recovery_catalog_owner ';
(Recover_catalog_owner,connect,resource)

3. Create a recovery directory

Oracle>rman Catalog Rman/rman
Rman>create catalog Tablespace rman_ts;
Rman>register database (database is target database)
Database registered in Recovery catalog
Starting full resync of recovery catalog
Full Resync Complete
Rman> Connect target/;
To use Backup and recovery later, you need to connect to two databases, which command:

Oracle>rman Target/catalog Rman/rman (the first slash represents the target database, catalog represents the catalog directory Rman/rman represents the catalog username and password)
Display after command execution:
Recovery manager:release 10.2.0.1.0-production on Wed Dec 10 15:00:42 2008
Copyright (c) 1982, +, Oracle. All rights reserved.
Connected to target database:ora10g (dbid=3988862108)
Connected to Recovery Catalog database

Command explanation:

The Shema of the schema in the database

List backup reads information from control

Crosscheck backup look at backup files and check that directories or files in Controlfile are actually on disk

Delete Backupset 24 24 represents Backupset's number, delete directory, delete your file

When using the Rman nocatalog backup oracle,oracle use Controlfile to store the backup information. Therefore, it is important to back up controlfile when using the Rman Nocatalog method.
Initialization parameter Control_file__record_keep_time set up the backup information to save the time, automatically clears the previous backup information at the specified time:
Sql> alter SYSEM set control_file_record_keep_time=7 scope=spfile;
There is a problem that when using Rman nocatalog recovery, the database must be in the "Mount" state. The prerequisite for Oracle startup mount is that control must exist. Therefore, you must restore the controlfile before restoring datafile. When you use the Rman catalog method, you can startup Nomount and then restore Controlfile, but you must first restore Controlfile in a file when you use Rman nocatalog.

The following is a comparison of the procedures for the recovery of Rman Nocatalog and Rman catalog to establish the correct backup strategy (the following recovery is a backup in online state):

Rman Nocatalog Recovery:

1 Establish an Oracle operating environment (including init or SP files)
2 file mode restore Controlfile to the location specified by the init file
3) Startup Mount
4) Rman, recovery datafile
5 ALTER DATABASE Open Resetlogs

Rman Catalog Recovery:

1 Establish an Oracle operating environment (including init or SP files)
2 Rman, restore Controfile
3 ALTER DATABASE Mount
4 Rman, restore datafile
5 ALTER DATABASE Open Resetlogs
As you can see, Rman nocatalog Backup, the Controlfile must be backed up in a file format.

In addition, the Control_file_record_keep_time value in the ORACLE parameter file (the default is 7 days) is recommended to be increased because the controlfile is used to store the backup information during Nocatalog, which is in the $oracle_home/dbs /initsid.ora (9i may also be in spfile and can only be changed through Oracle statements). This parameter control_file__record_keep_time set the backup information to save the time, automatically clears the previous backup information at the specified time.

Sql> Show Parameter control
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
Control_file_record_keep_time Integer 7
Control_files string d:/app/administrator/oradata/o
Control_management_pack_access string diagnostic+tuning
Sql> alter system set CONTROL_FILE_RECORD_KEEP_TIME=14 Scope=both;

The system has changed.

Sql> Select name,value,issys_modifiable from V$parameter where name= ' control_file_record_keep_time ';
name        value      ISSYS_MOD
------------ ----------------------
control_file_re   14         IMMEDIATE