Trail File Management

The Extract process captures the changes from the transaction logs of the source system (database) into trail files that are consumed by other Oracle GoldenGate processes.

Extract can write into one or multiple sets of trail files. A trail is a sequence of files that are created and aged as needed. Processes that read a trail are:

• Replicat: Replicat reads the trail file received on the target deployment.

• Distribution Service: Extracts data from a local trail for further processing, if needed, and transfers it to the target system.

• Receiver Service: Receives the trail and transfers to Replicat, which reads the trail and applies change data to the target database.

You can create more than one trail to separate the data of different tables or applications, or to satisfy the requirements of a specific replication topology, such as a cascading topology. You link tables specified with a TABLE statement to a trail specified with an EXTTRAIL parameter statement in the Extract parameter file.

• Assign Storage for Oracle GoldenGate Trails

• Estimate Space for the Trail

• Add a Trail

Also see Using the LogDump Utility to Access Trail File Records.