Oracle GoldenGate Upgrade Considerations
Before you start the upgrade, review the information about upgrading Oracle GoldenGate Extract and Replicat for Classic Architecture.
Even though you may only be upgrading the source or target, rather than both, all processes are involved in the upgrade. All processes must be stopped in the correct order for the upgrade, regardless of which component you upgrade, and the trails must be processed until empty.
In a unidirectional environment, it is a best practice to upgrade the target before upgrading the source.