How is a transaction defined in database management?

A transaction in database management is defined as a set of operations treated as a single logical unit. This means that all the operations within the transaction are executed together, ensuring that either all changes are committed to the database or none at all. This concept is crucial for maintaining data integrity and consistency, particularly in systems that involve multiple users or operations that could fail due to various reasons (such as power loss, system crashes, or concurrent access).

By considering a transaction as a single logical unit, the principles of atomicity, consistency, isolation, and durability (often referred to as the ACID properties) come into play. Atomicity ensures that the transaction is all-or-nothing—if any part of the transaction fails, the entire transaction can be rolled back. Consistency guarantees that a transaction takes the database from one valid state to another, maintaining its integrity. Isolation ensures that concurrently executed transactions do not affect each other, and durability ensures that once a transaction has been committed, its effects are permanent and survive subsequent system failures.

In contrast, defining a transaction as a series of operations that can fail independently approaches the concept incorrectly, as it does not reflect the importance of treating the operations as a single entity. A single operation that is always successful does not encaps