When implementing a bidirectional configuration, you must consider the following areas to avoid data integrity issues. These are as follows:
Loop detection
Conflict detection
Conflict resolution
Replicating Oracle sequences
Oracle triggers
Let's take a look at the first potential problem (data looping) and how to detect it.
GoldenGate has a built-in loop detection, which is configured through the IGNOREREPLICATES and GETAPPLOPS parameters to prevent local transactions from being replicated and causing endless loops. Another solution would be the TRANLOGOPTIONS EXCLUDEUSER parameter in the Extract process configuration, which effectively blocks the GGADMIN user on the target system (the user associated with the Replicat process). However, loop detection is only half the battle in a bidirectional environment. We must also consider conflict detection and resolution.