Backup & Recovery Flashcards

What is the primary purpose of Oracle RMAN (Recovery Manager)?

Answer: To perform backup and recovery tasks

Oracle Recovery Manager (RMAN) is a powerful command-line utility and framework specifically designed for backing up, restoring, and recovering Oracle databases. It simplifies and automates these critical tasks, ensuring data availability and integrity in case of failures. RMAN manages backup sets, image copies, and recovery catalogs efficiently.

What is an Oracle database archive log used for?

Answer: To store changes made to the database

Oracle database archive logs (also known as redo log files) store a historical record of all changes made to the database. These logs are crucial for database recovery, allowing the database to be restored to a specific point in time by reapplying transactions. They are essential for point-in-time recovery and maintaining data integrity after a media failure.

Which backup strategy provides the fastest recovery time?

Answer: Full backup with incremental backups

A full backup combined with incremental backups generally provides the fastest recovery time. The full backup serves as a complete baseline, and subsequent incremental backups only capture changes since the last backup. During recovery, the full backup is restored first, and then the incremental backups are applied in sequence, bringing the database up to date efficiently.

What does Oracle Flashback technology allow you to do?

Answer: Recover database to a specific point in time

Oracle Flashback technology allows users to view or revert database objects or the entire database to a previous point in time without needing to restore from a traditional backup. It provides various features like Flashback Query, Flashback Table, and Flashback Database, enabling quick recovery from logical errors or user mistakes by leveraging undo data.

What is the Oracle Data Guard feature used for?

Answer: Data protection and disaster recovery

Oracle Data Guard is a comprehensive solution for creating, maintaining, managing, and monitoring one or more standby databases to protect Oracle data from failures, disasters, and human errors. It ensures high availability, data protection, and disaster recovery capabilities by maintaining synchronized copies of the production database, allowing for rapid failover.

What is the difference between a hot backup and a cold backup in Oracle?

Answer: Cold backup occurs while the database is offline

A cold backup, also known as an offline backup, is performed when the Oracle database is shut down and completely offline. This ensures data consistency as no transactions are occurring during the backup process. In contrast, a hot backup (or online backup) is performed while the database is running and accessible to users.

Which Oracle tool helps you restore a database to a previous point in time?

Answer: RMAN

Oracle Recovery Manager (RMAN) is the primary and most robust tool for performing backup and recovery operations in Oracle databases. It can restore a database to a previous point in time, recover from various types of failures, and manage different backup strategies. RMAN is essential for ensuring database resilience and data integrity.

What should be included in a successful disaster recovery plan for an Oracle database?

Answer: Backup schedules, redundancy, and recovery procedures

A successful disaster recovery plan for an Oracle database must include comprehensive backup schedules to ensure data is regularly saved and recoverable. It also requires redundancy measures, such as Data Guard or Oracle RAC, to minimize downtime and provide high availability. Crucially, detailed recovery procedures are needed to guide the efficient restoration process after a disaster, ensuring business continuity.

What is an incremental backup in Oracle?

Answer: It only backs up data modified since the last backup

An incremental backup in Oracle only backs up data blocks that have changed since the last full or incremental backup. This strategy significantly reduces the backup window and storage requirements compared to full backups, as it only captures the delta of changes. It's an efficient way to maintain up-to-date backups with minimal overhead.