How does Oracle GoldenGate track changes in data?

Oracle GoldenGate can capture data changes through the following methods:

1. Capture and apply database data changes by configuring and enabling GoldenGate’s Extraction and Replicat processes. The Extraction process reads data changes from the source database and writes them to GoldenGate’s capture files (Trail File), while the Replicat process reads data changes from the capture files and applies them to the target database.
2. The GoldenGate file capture can be configured to use different formats for recording data changes, such as raw format, SQL format, or DDL format. Raw format can record changes to the entire data record, SQL format can record the SQL statements corresponding to the data changes, and DDL format can record changes to DDL statements.
3. GoldenGate allows for the configuration of filters to select the data changes that need to be captured and applied. These filters can be based on tables, columns, rows, or SQL conditions to filter the data changes.
4. GoldenGate can be configured to ensure transaction consistency in order to guarantee the order and consistency of data changes. Transaction consistency is achieved through GoldenGate’s sequence number (SEQNO) and operation sequence number (CSN).
5. GoldenGate can be configured to set up Checkpoints to keep track of data changes and progress. Checkpoints are useful for fault recovery and restarting GoldenGate.

In conclusion, Oracle GoldenGate can capture data changes by configuring and enabling Extraction and Replicat processes, selecting appropriate data formats, setting up filters, maintaining transaction consistency, and recording Checkpoints.