Online change synchronization extracts and replicates data changes continuously to maintain a near real-time target database. The number of Extract and Replicat processes and trails that you will need depends on the replication topology that you want to deploy and the process mode that you will be using.

For detailed information about deploying specific replication topologies, see:

• Using Oracle GoldenGate for Live Reporting

• Using Oracle GoldenGate for Real-time Data Distribution

• Configuring Oracle GoldenGate to Maintain a Live Standby Database

• Configuring Oracle GoldenGate for Active-Active Configuration

You may need to configure multiple Replicat processes if you are replicating between Oracle multitenant container databases.

You may need to configure multiple process groups to achieve a certain performance level. For example, you may want to keep lag below a certain threshold. Lag is the difference between when changes are made within your source applications and when those changes are applied to the target database.

Oracle GoldenGate supports up to 5,000 concurrent Extract and Replicat groups per instance of Oracle GoldenGate Manager. At the supported level, all groups can be controlled and viewed in full with GGSCI commands such as the INFO and STATUS commands. Oracle GoldenGate recommends keeping the number of Extract and Replicat groups (combined) at the default level of 300 or below in order to manage your environment effectively.

See Tuning the Performance of Oracle GoldenGate for more information about configuring Oracle GoldenGate for best performance.