Mumbai University > Information Technology > Sem 5 > Advanced Database Management System

Marks: 5M

Year: May 2015

ACID properties:

1. Atomicity:-
2. Execution of a transaction should be either complete or nothing should be executed at all i.e. either all the operations of transaction should be executed or none of them.
3. No partial transactions are allowed.
4. Consistency:-
5. Execution of transaction in isolation preserves the consistency of DB.
6. It is a state in which only valid data will be returned to database.
7. If due to some reasons, a transaction violates the DB consistency, entire transaction will be rollback and DB will be resorted to a consistent state.
8. Isolation
9. This property ensures that each transaction must remain unware of other concurrently executing team.

10. It keeps multiple transaction separated from each other until they are completed.

    For e.g.: When transaction changes bank account balance other transaction connect see the new balance until transaction commits.

11. Durability
12. This property guarantees that the database will keep track of change in such a way that server can recover from abnormal termination.

After a transaction completes successfully, the changes it has made to database persist, even if the system fails.