In database systems, what is a transaction?

A transaction in database systems refers to a sequence of operations that are executed as a single logical unit of work. This means that all the operations within the transaction must complete successfully for the transaction to be considered successful as a whole. If any part of the transaction fails, the entire sequence can be rolled back to maintain consistency in the database.

The concept of transaction is crucial in ensuring the integrity and reliability of data. It embodies the principles of the ACID properties—Atomicity, Consistency, Isolation, and Durability—which are fundamental to database transactions. Atomicity ensures that either all operations succeed or none at all, while consistency ensures that the database remains in a valid state. Isolation guarantees that transactions do not interfere with each other, and durability ensures that once a transaction has been committed, it remains permanent, even in the event of a system failure.

Overall, recognizing a transaction as a logical unit of work highlights its role in managing and maintaining data integrity, making it a critical aspect of database systems.