How Does Oracle Change Data Capture Work

 

Oracle Change Data Capture (CDC) is a feature of the Oracle database that detects and captures any changes made to the Oracle database including mentions, deletions, and updates.

This technology is apart of the Oracle replication process. Oracle CDC identifies and notes changes made to data in the relational format that is suitable for use in applications such as ETL, EAI, and more. Further, Oracle Change Data Capture is a cost-effective solution for organizations as it extracts and loads data into the data warehouse or other data storage repositories in real-time. Hence, there is no need to refresh full data in bulk whenever any modifications are made at the source.

There are two types of Oracle CDC. Each has different characteristics and businesses have to select one that matches their needs.

·        Synchronous Change Data Capture: It is done through triggers that are inserted into entries whenever data is modified in change table. These points are activated when any changes are noticed. The process starts by creating a user who acts as a change data publisher and has access to the tables at source and the namespace from where the changes are to be identified and captured. Next, change set and tables are created that subscribe to the changes. However, for this process to go through, a script has to be used that can develop the records and add the data to the target database.

·        Asynchronous Oracle CDC: This is done by redoing logs that keep a track of all the activities in a database. The advantage here is that the process is carried out without any drop in performance.

The type of Oracle CDC used by businesses is based on their requirements.