Transaction 

A transaction is a sequence of SQL statements that the database system treats as a unit. A transaction brings the database from one consistent state to another. If a transaction is interrupted, then the database system returns the database to the state it was in before the transaction began (ROLLBACK).

See also:

Concepts of the Database System, Transactions

SQL Reference Manual, Transactions

Database Administration in CCMS: MaxDB, Transactions

Database Administration in CCMS: SAP liveCache Technology, Transactions