Database transactions are a sequence of operations considered as a single unit of work. These operations either all complete successfully or all fail, ensuring data integrity and consistency of the database. Transactions possess four fundamental properties, typically described by the ACID model:
- Atomicity: All operations within a transaction either succeed completely or fail completely, without leaving intermediate states.
- Consistency: A transaction must ensure that the database transitions from one consistent state to another consistent state.
- Isolation: When multiple transactions execute concurrently, the execution of each transaction should not be interfered by other transactions.
- Durability: Once a transaction is committed, its results are permanent, even if the system fails, ensuring no data loss.
Transaction processing is an important mechanism in database management systems for ensuring data security and integrity.