Backup
and recovery are two pillars of Oracle database which helps to
protect your database against data loss and reconstruct the database.
Backup is a copy of data from your database that can be used to
reconstruct that data if any data loss condition occurs. Generally
for any database, Backups can be divided into two parts: physical
backups and logical backups.
Physical
backups are called backups of the physical files such as datafiles,
control files, and archived redo logs which is used to restore &
recover database,. Ultimately, the physical backup means copy of
files storing database information to some other location either on
disk or some offline storage such as tape.
Logical
backups contain logical data like tables or stored procedures
export (Oracle
export utility) from a database and stored in a binary file, for
later re-importing into a database using the corresponding Oracle
import utility.
In
this article, I am describing the methods to perform backup and
recovery based on physical backups, you have two solutions available:
First
one is RMAN that can back up all database files such as Datafiles,
Control files, Archived redo logs etc which is needed for efficient
recovery in the event of data loss. You can easily easily find in
ORACLE_HOME/bin directory. We can operate RMAN from Oracle Enterprise
Manager, or from command line.
Second
one is traditional user-managed backup and recovery used to directly
manage the files through OS commands to perform backup and restore
operations, and after that use SQL or SQL*Plus statements to recover
database.
You
can choose any one backup and recovery solution according to your
requirements. Check the features that you want to backup &
recover your database:
Feature
|
RMAN
|
User-Managed
|
Closed
database backups
|
Supported.Requires
instance to be mounted.
|
Supported.
|
Open
database backups
|
Supported.
No need to use BEGIN/ END Backup statements
|
Supported.
Must use BEGIN/ END Backup statements
|
Incremental backups
|
Supported.
|
Not
supported.
|
Corrupt
block detection
|
Supported.
Identifies corrupt blocks and logs in V$DATABASE_BLOCK_CORRUPTION.
|
Not
supported.
|
Automatic
record
|
Supported.
Establishes the name and locations of files to be backed up (whole
database, tablespace, datafile or control file backup).
|
Not
supported. Files to be backed up must be specified manually.
|
Recovery
catalogs
|
Supported.
Backups are recorded in the RMAN repository, which is contained in
the control file and optionally in the recovery catalog database.
|
Not
supported. DBA must keep own records of backups.
|
Backups
to media manager
|
Supported.
Interfaces with a media manager. RMAN is also supports proxy
copy, a media manager. a feature that allows the media manager to
manage the transfer of data.
|
Supported.
Backup to tape is manual or controlled by a media manager
|
Backs
up initialization parameter file
|
Supported.
|
Supported.
|
Backs
up password and networking files
|
Not
Supported.
|
Supported.
|
Platform-independent
language for backups
|
Supported.
|
Not
Supported.
|
Most
of the users thinks that RMAN is very complicated but in actual it is
very easy,even also Oracle
recommended using RMAN to take oracle database backup & recovery
Because there are many options for oracle database backup which are
not available in User Managed. So As
per my view, RMAN is one the best way to recover oracle database.
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