ACID Properties in DBMS

A transaction is expected to contain certain properties that are called ACID Properties of Transactions. There are four properties of ACID Properties of Transactions are listed as below :

  • Atomicity
  • Consistency
  • Isolation
  • Durability

transaction states


The atomicity of a transaction implies that it will run to completion as an individual unit (atomic unit). At the end of a unit of the transaction either there is no change to the database or the database has been changed in a consistent manner. No changes will be reflected in the database in the middle of the execution of an atomic unit of transaction.


Consistency property of a transaction implies that if a database was in the consistent state before the execution of the transaction, then after execution of the transaction also, the database will be in the consistency state.


Isolation property of a transaction process implies that actions performed by a database will be isolated or hidden from other transactions or processes until it is either executed or terminated. This property gives the transaction a measure of relative independence.


Durability property of a database transaction implies that the updates made by a transaction will be reflected in the database on the termination of committed action. Therefore, any loss or failure after the committed action will not cause loss of updates made by the transaction. Rollback of the transaction can’t be performed, if the transaction has Durability property.