Introduction to RMAN Interview Interview Questions and Answers
RMAN stands for the Recovery Manager. It is an Oracle Database client that is used for the backup and recovery tasks on our databases, and it can also automate the administration of our backup strategies. Managing the production database’s restoring, backing up, and recovering various database files can easily be done with the help of rman. It helps to simplify the DBA jobs in many companies.
If you are looking for a job related to RMAN Interview, you need to prepare for the 2021 RMAN Interview Questions. Every interview is indeed different as per the different job profiles. Here, we have prepared the important RMAN InterviewInterview Questions and Answers, which will help you succeed in your interview.
This 2021 RMAN Interview Questions article will present the 10 most important and frequently used RMAN interview questions. These questions are divided into two parts are as follows:
Part 1 – RMAN Interview Questions (Basic)
This first part covers basic Interview Questions and Answers.
Q1. What are the main features of RMAN?
Rman provides us access to various kinds of backup, recovery techniques, and many other features also. Few of them listed below.
- Automatic specification for various files to include in a backup: A setting of the name and location for backup files happens automatically in RMAN.
- Compression Unused block: It is one of the RMAN features, which gives provision to skip blocks of the data that have never been used.
- Backup repository Maintained: Backups are recorded in the control file, which is the main repository of RMAN metadata. Controlfile In RMAN, where all the data are back up. This file is also called the main repository of the Metadata of the RMAN. It also has a recovery catalog to store the metadata.
- Binary compression OF the Backup: It is a process in which a reduction of the size of data backups happened, and this is associated with Oracle Database.
- Incremental backups: it backup’s only data blocks changed since a previous backup.
Therefore, it speeds up compact backups and faster recovery.
- Media recovery: The recovery of the data file has only a small number of corrupt data blocks without taking it offline or restoring it from backup.
- Backups in the Encrypted format: RMAN provides backup with the data in encryption format, it is integrated into Oracle Database, it is used to store backup sets in an encrypted format.
- Corrupt block detection Features: Rman can check the corrupted block before taking its backup.
Q2. Explain the expired backup and obsolete backup?
In RMAN, expired status means backup data, details backup is not present at the destination, while obsolete means backup information present or found it is not needed currently. This is because RMAN has been configured so that it will not need backup information after the particular number of days elapsed.
Q3. Explain the Level 0, Level 1 backups in?
A level 0 is called an incremental backup, which is the base for the upcoming subsequent incremental backups; copies all blocks containing data after that is backup whole data as backup.
A level 1 can be one of the type explained below:
It may be the Differential backup, which helps to backs up all blocks changed after the most recent incremental backup at level 1 or
It may be the cumulative backup, In which backs up all blocks changed after the most recent incremental backup at level 0
Q4. Is it possible to take a backup when it is in down status?
This is the basic RMAN Interview Question asked in an interview. Please find below the different tables that RMAN supports are. We can take RMAN backup only when the target database is Open or in the Mount stage. The reason behind this is RMAN keeps the backup metadata in the control file. Only in an open or mount mode control file is accessible. So it is not possible to take backup in down status.
Q5. Tell the file’s that RMAN can back up as well as the cant back up?
RMAN can backup Data files, Archive logs, standby database Spfile, control file, etc. Files that cannot be taken as a backup are the following p file, network configuration files, Redo logs, password files, external tables, and the Oracle home files’ contents.
Part 2 – RMAN Interview Questions (Advanced)
Let us now have a look at the advanced Interview Questions.
Q6. How do we can detect corruption of the block in the RMAN database? What are the steps to fix this?
The first step to finding out the corrupted block using the command v$block_corruption; with the help of this command, we can find all the corrupted blocks. In the next step, we have to recover it by the command RMAN> block recover data filename <fileid> block <blockid>;
The above commands will helps us to recover all corrupted data.
Q7. What are the steps to install the RMAN recovery catalog?
Following the Steps to be followed to install the RMAN.
- First, create a connection string in the catalog database.
- At the catalog database, create one new user or use existing users and give that user a recovery_catalog_owner privilege.
- Login into RMAN with a connection string
- export ORACLE_SID
- rman target catalog @connection string
- rman> create catalog
- register database
Q8. Explain the Architectural components of RMAN, and what are the channels?
The architecture components of the RMAN are listed below.
- Media management Layer (optional)
- RMAN Executables
- Server process
- Backups, backup sets, and backup pieces
- Target database
- Recovery catalog database (optional)
It is an RMAN Server, which is responsible for performing lots of work in RMAN; it starts when required to perform input-output. This is possible to through communication with input and output devices which may be different storage devices. It used to reading and writing of backup files into these stores. It whole process is performed by allocation channel to I/O devices.
- It is the maximum rate at which files read.
- It is the number of processes simultaneously accessing I/O devices.
- It is the maximum size of files created on I/O devices.
- Maximize the number of files open at a time
Q9. Explain the reason why is the catalog optional in RMAN?
This is the most asked RMAN Interview Question in an interview. Since RMAN manages backup and recovery operations, it requires storing necessary information about the database and its related metadata. In RMAN, this information stored in the control file of the target database. In the RMAN recovery catalog schema, which is used to recover the data stored in a separate database to be safe from other databases that may be corrupt, .it is separated from the target database.
Q10. Explain the RMAN Backup set?
It can be called a logical group of many backup files. These files are created with RMAN backup commands when used to take backup. In RMAN backup set is a collection of various backup-related files that are associated with backup. It is built with collections of commands.
This has been a guide to the list Of RMAN Interview Questions and Answers so that the candidate can crackdown these Interview Questions easily. Here in this post, we have studied top RMAN Interview Questions, which are often asked in interviews. You may also look at the following articles to learn more –