Collecting the plural processing which it is related to one processing unit, fourqualities which are requiredfrom the transaction processing which it manages. "Atomicity" (atomic characteristic), "Consistency" (coherence), "Isolation" (independence), those which connect the initial "of Durability" (durability).

Atomicity (atomic characteristic and non- divisibility)is the character that the individual procedure which is included in transaction "is entirely executed" "is not executed also one" becomes either state.

It is the character where a state where Consistency(coherence), consistency of the data is maintained at front and back of transaction,