Apply Process Considerations

The cause of poor replication performance is often a poorly performing apply process. Oracle has been improving the internal workings of the apply process over the past releases. Some of these improvements include applying changes to the destination tables without actually invoking the SQL engine, defaulting the apply process to run with parallelism set to 4, and applying independent transactions simultaneously. These improvements make the apply process in Oracle Database 11g R2 highly efficient. However, there are a few other things you can explore to improve the performance of the apply process, as discussed in this section.

Tuning Apply Process Parameters

There are some apply process parameters that can affect the performance of the apply process. Changes to their values should be considered based on the type of the workload, available resources (CPU and memory), and the replication latency requirements.