Oracle DBA Backup and Recovery Interview Questions - 1

Question: 1

What is instance recovery?

Instance recovery is used in Real Application cluster (RAC) environment only.

It occurs in an open database when one instance detects that another instance has crashed.

Question: 2

What is complete recovery?

Complete recovery uses redo data or incremental backups combined with a backup of a database, datafile or tablespace to update it to the most current point in time.

Oracle applies all the redo changes contained in the archived and online logs to the backup.

During a complete recovery, all the changes made to the restored file since the time of the backup are redone.

Question: 3

What is full backup?

A full backup is a backup of all the datafiles, control files and SPFILE.

A full backup can be made with RMAN or the operating system commands while the database is open or closed.

As a rule, you must perform full backup, if your database is not running in the archiving log mode.

Question: 4

What is a recovery catalog?

Recovery catalog is an inventory of the backup taken by RMAN for the database.

It is used to restore a physical backup, reconstruct it, and make it available to the Oracle server.

Question: 5

What are channels?

RMAN process uses channel to communicate with I/O devices.

You can control the type of I/O device, parallelism, number of files and size of files by allocating channels.