1 day ago
Sharese Moye
RE: Week 10 Discussion
Top of Form
Commit makes permanent changes to the data once a transaction is completed. On the other hand, Rollback is an undo command to return data back to the previous state before it is committed. A business scenario is an online retailer wants to archive customer email addresses from those that have submitted to be removed from retailer list, but deletion query was performed instead. If this error is identified prior to the ‘commit’ command executed, the rollback option can return the database to a previous state prior to the invalid transaction and the appropriate query can be run at a later time. Another example could be a bank. Customers have multiple simultaneous transactions causing a deadlock. Multiple transactions are waiting for access to the locked data and there is a system failure. A rollback may be necessary if transaction is flagged as fraudulent.
Rollback feature can be used during data recovery to undo any uncommitted transactions that may have occurred during instances such as a power outage or database corruption event. The ability to ensure database recovery helps business continuity by enabling the database to return to a consistent state. Concurrency controls are used to manage transactions that occur at the same time. The timestamp method is used to assign a unique identifier to a transaction. This can be essential to data recovery where failed or incomplete transactions can be rolled back to return a database to a consistent state at a particular time.
Geeksforgeeks.February 3, 2022.Failure Classification in DBMS.https://www.geeksforgeeks.org/failure-classification-in-dbms/#:~:text=There%20are%20many%20reasons%20that,)%2C%20software%20errors%2C%20etc
Bottom of Form
