If you do not suspend transaction processing for the active database while initializing the standby database, choose the “dump marker” option when you add the standby database.
Then initialize the standby database by using the dump and load commands.
Replication Server starts replicating into the standby database from the first dump marker after the "enable replication" marker in the transaction log of the active database.
In this figure, transaction T1, executed after you added the standby database, appears after the enable replication marker in the log. T1 is included in dumps, so it is present in the standby database after you have loaded the dumps. Replication Server does not need to replicate it into the standby database.
Transactions can be executed in the active database between the time the enable replication marker is written and the time the data in the active database is dumped.
You can load the last full database dump and any subsequent transaction dumps into the standby database until both markers have been received and the standby database is ready for operation. Then, optionally, you can use a final transaction dump of the active database to bring the standby database up to date. Any transactions not included in dumps will be replicated.
Replication Server does not replicate transactions from the active to the standby database until it has received both the enable replication marker and the first subsequent dump marker. After receiving both markers, Replication Server starts executing transactions in the standby database.