Backup and Recovery Concepts

Basic Backup and Recovery Concepts

In general, backup and recovery refers to the various strategies and procedures involved in protecting your database against data loss and reconstructing the data should that loss occur. Click on the above link to read more and to become a Oracle DBA.

Errors and Failures Requiring Recovery

Several problems can halt the normal operation of an Oracle database or affect database I/O operations. The following sections describe the most common types of problems.Click on the above link to read more and to become a Oracle DBA.

Data Structures Used for Recovery

Several structures of an Oracle database safeguard data against possible failures. This section introduces each of these structures and its role in database recovery. Click on the above link to read more and to become a Oracle DBA.

Database Archiving Modes

A database can operate in two distinct modes: NOARCHIVELOG mode (media recovery disabled) or ARCHIVELOG mode (media recovery enabled). Click on the above link to read more and to become a Oracle DBA.

Whole Database and Partial Database Backups

A whole database backup includes backups of the current control file along with all datafiles. Whole database backups are the most common type of backup. Click on the above link to read more and to become a Oracle DBA.

Consistent and Inconsistent Backups

You can use RMAN or operating system commands to make an inconsistent backup or a consistent backup. An inconsistent backup is a backup of one or more database files that Oracle DBA make while the database is open or after the database has shut down abnormally. Click on the above link to read more and to become a Oracle DBA.

Online, Offline, RMAN and User Managed Backups

You can back up all or specified datafiles of an online tablespace while the database is open, but only when the database runs in ARCHIVELOG mode. Click on the above link to read more and to become a Oracle DBA.

Types of Oracle Recovery

Crash recovery is used to recover from a failure either when a single-instance database crashes or all instances of an Oracle Real Application Clusters database crashes. Click on the above link to read more and to become a Oracle DBA.

Redo Application During Recovery

Database buffers in the buffer cache in the SGA are written to disk only when necessary, using a least-recently-used (LRU) algorithm. Click on the above link to read more and to become a Oracle DBA.

complete and incomplete recovery

Media recovery updates a backup to either to the current or to a specified noncurrent time. When performing media recovery, you can recover the whole database, a tablespace, or a datafile. In any case, you always use a restored backup to perform the recovery Click on the above link to read more and to become a Oracle DBA.

RMAN and User-Managed Restore and Recovery

Oracle DBA can use the RMAN utility to restore and recover the database orRestore backups by means of operating system utilities, and then recover by executing the SQL*Plus RECOVER command . Click on the above link to read more and to become a Oracle DBA.

Oracle Backup Strategies

Before you create an Oracle database, decide how to protect the database against potential media failures. If you do not develop a backup strategy before creating your database, then Oracle DBA may not be able to perform recovery if a disk failure damages the datafiles, online redo log files, or control files. Click on the above link to read more and to become a Oracle DBA.

Restore and Recovery Strategies

Oracle provides a variety of procedures and tools to assist you with recovery. Click on the above link to read more and to become a Oracle DBA.

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