An online migration enables you to perform database migration without any downtime of your source database.

To take advantage of parallelism and achieve the best data transfer performance, Oracle recommends that you transfer data using Object Store for databases over 50GB in size. The database link transfer medium can be convenient for smaller databases, but this choice may involve uncertainty in performance because of its dependence on network bandwidth for the duration of the transfer.

As part of a migration job, Database Migration uses GoldenGate's replication technology to facilitate database replication between the source and target databases.

When the application switches over to the target database, Database Migration tears down the replication so that the target database in the Cloud can then be used as the production database. Note that bi-directional synchronization is not currently supported. Synchronization is always from the source database to the target database.

Note that Online migration using GoldenGate Marketplace instances require SQL*Net connectivity from the GoldenGate host running in the target tenancy to the source database.