■ Atomic—Transactions are made up of one or more activities bundled
together as a single unit of work. Atomicity ensures that all the operations
in the transaction happen or that none of them happen. If all the activities
succeed, the transaction is a success. If any of the activities fail, the entire
transaction fails and is rolled back.
■ Consistent—Once a transaction ends (whether successful or not), the system
is left in a state that is consistent with the business that it models. The data
should not be corrupted with respect to reality.
■ Isolated—Transactions should allow multiple users to work with the same
data, without each user’s work getting tangled up with the others. Therefore,
transactions should be isolated from each other, preventing concurrent
reads and writes to the same data from occurring. (Note that isolation
typically involves locking rows and/or tables in a database.)
■ Durable—Once the transaction has completed, the results of the transaction
should be made permanent so that they will survive any sort of system crash.
This typically involves storing the results in a database or some other form
of persistent storage.
together as a single unit of work. Atomicity ensures that all the operations
in the transaction happen or that none of them happen. If all the activities
succeed, the transaction is a success. If any of the activities fail, the entire
transaction fails and is rolled back.
■ Consistent—Once a transaction ends (whether successful or not), the system
is left in a state that is consistent with the business that it models. The data
should not be corrupted with respect to reality.
■ Isolated—Transactions should allow multiple users to work with the same
data, without each user’s work getting tangled up with the others. Therefore,
transactions should be isolated from each other, preventing concurrent
reads and writes to the same data from occurring. (Note that isolation
typically involves locking rows and/or tables in a database.)
■ Durable—Once the transaction has completed, the results of the transaction
should be made permanent so that they will survive any sort of system crash.
This typically involves storing the results in a database or some other form
of persistent storage.
Comments
Post a Comment