In database, a database transaction is a logical unit of database operations which are executed as a whole to process user requests for retrieving data or updating the database.
Transaction should have four properties: atomic, consistent, isolated and durable. These properties of database transactions are often referred to by the acronym ACID.
Atomicity: A transaction is an indivisible unit. It is included in all operations or have done or not done.
Consistency: Transaction must keep the database from one consistent state to another consistent state variable. Consistency is closely relatedÂ to atomicity.
Isolation:Â A transaction is implemented and can not be interfered with by other transactions. That is, an internal operation of a transaction and the use of the data is isolated with other transaction, the concurrent implementation of all transactions can not interfere between with each other.
Durability: It's also called permanence. It refers to a transaction which is submitted, and the data in the database it charges should be permanent. The next operation or other faults should not have any impact on them.
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