Four characteristics and meanings of database transactions "detailed"

This article introduces four characteristics and meanings of database transactions. We can refer to Topic.alibabacloud.com's MySQL video tutorial and MySQL manual!

Four characteristics and meanings of database transactions

The database transaction transanction four basic elements that are correctly executed.

ACID

Atomicity (atomicity)

Atomicity: All operations in the entire transaction, either complete or complete, are not likely to stall in the middle of the process. When an error occurs during execution, the transaction is rolled back (Rollback) to the state before the transaction begins, as if the transaction had never been executed.

Consistency (correspondence)

Consistency: The integrity constraints of the database are not compromised until the transaction begins and after the transaction has ended.

Isolation (Isolation)

Isolation: The isolated state performs transactions so that they appear to be the only operations that the system performs within a given time. If there are two transactions that run at the same time and perform the same function, the isolation of the transaction will ensure that every transaction in the system considers only that the transaction is in use by the system. This attribute is sometimes called serialization, and in order to prevent confusion between transactional operations, the request must be serialized or sequenced so that only one request is used for the same data at a time.

Persistence (Durability)

Persistence: After the transaction is completed, changes made to the database by the firm are persisted in the database and are not rolled back.