Database Recovery Techniques
After a failure or corruption, database recovery is the process of returning a database to a consistent condition. In order to preserve system integrity, commit transactions, and ensure accurate data, it entails restoring the database to its previous state. To accomplish successful database recovery, a number of strategies are used, each designed to handle particular failure scenarios.
Types of Database Recovery Techniques
1. Backup and Restore
Regular backups are one of the core database recovery strategies. At predetermined periods, organizations make backup copies of their databases. These backups can be used to restore the database to a previous state in the event of data loss or corruption. However, the frequency of backups and the capacity to reduce data loss in between backup intervals determine how effective this strategy is.
2. Transaction Log Processing
All database modifications are documented in transaction logs, which enables businesses to roll forward or replay transactions in the case of an error. By reapplying committed transactions to the database, this method guarantees that it returns to a consistent state. Processing transaction logs is especially useful for point-in-time recovery, which enables businesses to restore databases to a given point in time.
3. Check point Mechanism
Checkpoint techniques are frequently used by database management systems (DBMS) to establish a consistent point in the transaction log. By showing a consistent state from which the system can rapidly recover in the event of a breakdown, checkpoints aid in reducing the recovery time. The amount of transaction log processing needed for recovery is decreased by regular checkpoints.
4. Shadow Paging
A shadow or duplicate copy of the complete database is kept up to date using the shadow paging approach. Only once the transaction is committed are the changes atomically exchanged with the original database after they have been applied to the shadow copy. Data consistency is ensured by the system's ability to fall back to the original shadow copy in the event of an error.
5. Database Replication
Keeping duplicate copies of the database on different servers is known as database replication. Traffic can be forwarded to the copy in the case of a failure, guaranteeing business continuity. Replication improves load balancing and data availability in addition to being a recovery tool.
6. Point-in-Time Recovery
Point-in-time recovery enables businesses to take a database back to a particular point in time prior to a disaster. This method works best when data corruption is discovered after it has already happened and companies need to restore the database to its pre-corrupt condition.
