Implicit Transaction Processing

Controlling Transactions :



An automatic commit occurs under the following circumstances :

• DML is issued
• DDL statement is issued
• DCL statement is issued
• Normal exit from psql, without explicitly issuing COMMIT or ROLLBACK statements
• An automatic rollback occurs under an abnormal termination of psql or a system failure.

System Failures :

• When a transaction is interrupted by a system failure, the entire transaction is automatically rolled back. This prevents the error from causing unwanted changes to the data and returns the tables to their state at the time of the last commit. In this way, the PostgreSQL server protects the integrity of the tables.