What is meant by the durability principle in transaction processing?

The durability principle in transaction processing is fundamental to the integrity of databases, particularly in ensuring that once a transaction has been committed, it remains so, even in the event of failures in the system, such as software or hardware crashes. This principle assures that the changes made to the database are permanent and will persist despite any unforeseen disruptions.

Durability is essential for maintaining trust in a system where financial transactions or critical data processing occurs because it guarantees that all completed transactions are recorded accurately and cannot be lost. For instance, if a financial transaction is confirmed and then a power outage occurs, the durability principle ensures that the transaction's effects are not lost, and the data remains consistent and recoverable.

Understanding this principle is crucial, particularly in contexts where data integrity is paramount, such as banking systems, e-commerce platforms, and other transaction-heavy applications.