The first time that Oracle database offered the CDC technology as a built-in feature was when it released the Oracle 9i version. It helped to track and record all changes made in user tables in a database. These changes were then stored in changed tables for use in ETL applications and could be loaded into databases and data warehouses after being processed.

The mechanism of the Oracle Change Data Capture after it was launched was based on triggers placed in the source tables. However, this process did not find favor with Database Administrators who found the process to be too intrusive.

The next form of Oracle Change Data Capture was released by Oracle with their 10g version and it was less intrusive than the first. It worked by leveraging the redo logs of the source database. The revised system for Oracle Change Data Capture was called Oracle Streams. It could detect and transfer change data to a target database without adversely affecting the performance of the source database.

This model of Oracle CDC was received favorably by developers and DBAs but surprisingly, Oracle decided to discontinue Oracle Streams after it released the 12c version and Oracle CDC was no longer supported by it. The option provided to users was to pay for Oracle Golden Gate or decide to go for any other Oracle replication and CDC method for CDC.

Currently, the structure of Oracle Change Data Capture is such that when the data in one computer changes, another computer has to take some type of action that is based on that change. The first computer is called the source database and the second is the target database.