In computer science, ACID (atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequence of database operations that satisfies the ACID properties (which can be perceived as a single logical operation on the data) is called a transaction.
| ACID | |
|---|---|
| atomicity | guarantees that each transaction is treated as a single “unit” (atomic), which either succeeds completely or fails completely |
| consistency | Consistency ensures that a transaction can only bring the database from one consistent state to another. |
| isolation | Isolation ensures that concurrent execution of transactions leaves the database in the same state that would have been obtained if the transactions were executed sequentially. |
| durability | Durability guarantees that once a transaction has been committed, it will remain committed even in the case of a system failure (e.g., power outage or crash). |