Use Change Data Capture to simplify ETL in data warehouse applications.
The Oracle Change Data Capture (CDC) feature simplifies the process of identifying the change data since the last extraction. CDC provides easy-to-use APIs to set up a CDC environment. If you are a DBA or a developer involved in a data integration project that involves the regular extraction and transportation of a large amount of data from one system to another system or systems, consider CDC to help reduce your ETL time.
The CDC feature was introduced in Oracle9i Database. CDC helps identify the data in the source system that has changed since the last extraction. With CDC, data extraction takes place at the same time the INSERT, UPDATE, or DELETE operations occur in the source tables, and the change data is stored inside the database in change tables. The change data, thus captured, is then made available to the target systems in a controlled manner, using database views.