• Atomicity: Each transaction will be all or nothing. If one part fails, no changes are persisted on the database.
• Consistency: Changes to the data through transactions need to guarantee its consistency.
• Isolation: The result of concurrent execution of transactions results in a system state that would be obtained if the transactions were executed serially.
• Durability: Once the transaction is committed, the data persists.

Patterns used:

• Data Mapper: use of repositories to retreive data.
• Active Record: use of model to access the database.