ACID - Durability

ACID - Durability


Durability is the final ACID property guaranteeing that once a transaction has been successfully committed, the changes are permanent and will survive any subsequent system failures, restarts, or power losses. This permanence is fundamentally ensured by the transaction log, which functions as an immutable record permanently logging all changes made to the data.



Permanent Record: Durability guarantees that data changes are persistent and that the committed state of the table cannot be lost due to later operational incidents.

Mechanism (Immutable Log): The underlying mechanism in Delta Lake is the immutable transaction log, which permanently records every change, thereby ensuring durability.

Enables Auditing: The permanent record of every atomic transaction within the transaction log makes features like Time Travel possible, allowing users to query previous versions of a table and providing a crucial mechanism for audit history.