Configure Recovery Settings

Before You Begin

This 15-minute tutorial shows you how to configure the Fast Recovery Area, set the database in ARCHIVELOG mode, and enable Flashback Database.

Select the Oracle Database release:

Background

Oracle Recovery Manager (RMAN), a command-line tool, is the method preferred by Oracle for efficiently backing up and recovering your Oracle database. The files protected by the backup and recovery facilities built into RMAN include data files, control files, server parameter files, and archived redo log files. With these files you can reconstruct your database.

What Do You Need?

Oracle Database 18c19c

Configure the Fast Recovery Area

Open a terminal window. Execute the oraenv utility to set the environment variables for the orcl database.
```
$ . oraenv
ORACLE_SID = [oracle] ? orcl
The Oracle base has been set to /scratch/u01/app/oracle
```

Invoke SQL*Plus and log in as the SYSTEM user.

$ sqlplus system

SQL*Plus: Release 18.0.0.0.0 - Production on Thu Mar 28 03:04:00 2019
Version 18.3.0.0.0

Copyright (c) 1982, 2018, Oracle.  All rights reserved.

Enter password: 
Last Successful login time: Thu Mar 28 2019 02:54:20 -07:00

Connected to:
Oracle Database 18c Enterprise Edition Release 18.0.0.0.0 - Production
Version 18.3.0.0.0

SQL>  SQL*Plus: Release 19.0.0.0.0 - Production on Mon Jul 15 01:08:39 2019
Version 19.3.0.0.0

Copyright (c) 1982, 2019, Oracle.  All rights reserved.


Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0

SQL>

Use the following SQL*Plus command to view the settings for all initialization parameters containing "recovery" in the name.

QL> show parameter recovery

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest                string      /scratch/u01/app/oracle/recove
                                                 ry_area
db_recovery_file_dest_size           big integer 12918M
recovery_parallelism                 integer     0
remote_recovery_file_dest            string

DB_RECOVERY_FILE_DEST

Set the Fast Recovery Area size to 10GB by executing the following command.

SQL> alter system set db_recovery_file_dest_size=10G;

System altered.

SQL> show parameter recovery

                                                                                                                                                                                                     
NAME                                 TYPE        VALUE                                                                                                                                               
------------------------------------ ----------- ------------------------------                                                                                                                                
db_recovery_file_dest                string      /scratch/u01/app/oracle/recove                                                                                                                                
                                                 ry_area                                                                                                                                                       
db_recovery_file_dest_size           big integer 10G                                                                                                                                                           
recovery_parallelism                 integer     0                                                                                                                                                             
remote_recovery_file_dest            string

Enable Archiving of Redo Log Files

Open a terminal window. Invoke SQL*Plus and connect as the SYSDBA user.

$ . oraenv
ORACLE_SID = [oracle] ? orcl
The Oracle base has been set to /scratch/u01/app/oracle
$ sqlplus / as sysdba

SQL*Plus: Release 18.0.0.0.0 - Production on Thu Mar 28 03:04:00 2019
Version 18.3.0.0.0

Copyright (c) 1982, 2018, Oracle.  All rights reserved.

Enter password: 
Last Successful login time: Thu Mar 28 2019 02:54:20 -07:00

Connected to:
Oracle Database 18c Enterprise Edition Release 18.0.0.0.0 - Production
Version 18.3.0.0.0

SQL>  SQL*Plus: Release 19.0.0.0.0 - Production on Mon Jul 15 01:08:39 2019
Version 19.3.0.0.0

Copyright (c) 1982, 2019, Oracle.  All rights reserved.


Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0

SQL>

Execute the following command to determine whether your database is in ARCHIVELOG mode.

SQL> archive log list
Database log mode              No Archive Mode
Automatic archival             Disabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     41
Current log sequence           43
SQL>

Switch to the RMAN terminal and execute the following command to shut down the database instance.

RMAN> shutdown immediate

using target database control file instead of recovery catalog
database closed
database dismounted
Oracle instance shut down.

Execute the following command to start the instance and mount the database.

RMAN> startup mount

connected to target database (not started)
Oracle instance started
database mounted

Total System Global Area    3355443200 bytes

Fixed Size                     8791392 bytes
Variable Size               1862273696 bytes
Database Buffers            1476395008 bytes
Redo Buffers                   7983104 bytes

Execute the following command to create a backup before you change the ARCHIVELOG mode.
```
RMAN> backup database;
```
Click output.txt to view the output.
Execute the following command to put the database in ARCHIVELOG mode.
```
RMAN> alter database archivelog;

Statement processed
```
Execute the following command to open the database.
```
RMAN> alter database open;

Statement processed
```

Return to your SQL*Plus session (You might need to re-connect to sqlplus / as sysdba). Verify if the database is in ARCHIVELOG mode.

SQL> connect / as sysdba
Connected.

SQL> archive log list;
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     41
Next log sequence to archive   43
Current log sequence           43
SQL>

Exit SQL*Plus.
Return to your RMAN session. Back up the database by executing the following command.
```
RMAN> backup database plus archivelog;
```
Click output.txt to view the output.

Enabling Flashback Database

Invoke RMAN and connect to the target database as the SYSBACKUP user.

$ rman target sysbackup
Recovery Manager: Release 18.0.0.0.0 - Production on Thu Mar 28 21:54:00 2019
Version 18.3.0.0.0

Copyright (c) 1982, 2018, Oracle and/or its affiliates.  All rights reserved.

target database Password: enter password
connected to target database: ORCL (DBID=1530541453)

RMAN> Recovery Manager: Release 19.0.0.0.0 - Production on Thu May 28 21:54:00 2019
Version 19.3.0.0.0

Copyright (c) 1982, 2019, Oracle and/or its affiliates.  All rights reserved.

target database Password: enter password
connected to target database: ORCL (DBID=1530541453)

RMAN>

Optionally, specify the length of the desired flashback window (in minutes) by setting the DB_FLASHBACK_RETENTION_TARGET initialization parameter. The default value for this parameter is 1440 minutes, which is one day. This example sets the flashback window to 3 days:
```
RMAN> alter system set db_flashback_retention_target=4320;

using target database control file instead of recovery catalog
Statement processed
```
Enable Flashback Database by executing the following command.
```
RMAN> alter database flashback on;

Statement processed
```