Principles
Atomic
Each transaction is either properly carried out or the process halts and the database reverts back to the state before the transaction started. This ensures that all data in the database is valid.
Consistent
A processed transaction will never endanger the structural integrity of the database.
Constraints:
- Referential Integrity
- Validation Rules
Isolated
Transactions do not contend with one another. Contentious access to data is moderated by the database so that transactions appear to run sequentially.
Prevents inconsistencies (e.g. race conditions) caused by multiple concurrent actions
- Dirty reads (reading outdated data)
- Phantom reads (reading in unexpected data)
Durable
*The data related to the completed transaction will persist even in the cases of network or power outages. If a transaction fails, it will not impact the manipulated data.