databastransaktion

A database transaction is a sequence of one or more operations performed on a database that is treated as a single unit of work. These operations are executed in a way that ensures the database remains in a consistent state, even in the event of a failure. Transactions are fundamental to maintaining data integrity and are widely used in database management systems.

The key properties of a transaction, often referred to by the acronym ACID, are:

- Atomicity: Ensures that all operations within a transaction are completed successfully. If any operation fails, the entire transaction is rolled back, and the database remains unchanged.

- Consistency: Guarantees that a transaction brings the database from one valid state to another, maintaining predefined rules and constraints.

- Isolation: Ensures that the operations within a transaction are isolated from other transactions, preventing interference and maintaining data integrity.

- Durability: Once a transaction is committed, its changes are permanent and survive any subsequent system failures.

Transactions are initiated with a BEGIN TRANSACTION statement and are completed with either a COMMIT or ROLLBACK statement. A COMMIT makes all changes made during the transaction permanent, while a ROLLBACK undoes all changes, restoring the database to its state before the transaction began.

Database transactions are essential in various applications, including banking systems, e-commerce platforms, and inventory management systems, where maintaining data accuracy and consistency is crucial. They provide a mechanism to handle complex operations that require multiple steps, ensuring that either all steps are completed successfully or none are, thus preserving the integrity of the database.