Transactions - SQL Considerations (Magic xpa 3.x)
A transaction is a sequence of one or more SQL statements that are usually closely related but perform interdependent actions and which form a logical unit of work. Each statement in the transaction performs some part of a task, but all of the statements are required to complete the task. The DBMS executes the sequence as one operation because the statements are grouped as a single unit. All the statements must be completed for the database to remain consistent.
When applications update multiple tables in a database, transactions ensure database integrity.
The Transaction Mechanism
Locking - SQL Considerations
Databases
The Data Management and Magic xpa concept paper