delta_datashipping

This mode establishes a system replication where occasionally (per default every 10 minutes) a delta data shipping takes place in addition to the continuous log shipping. The shipped redo log is not replayed on the secondary site.

logreplay

In this operation mode a redo log shipping is done after system replication was initially configured with one full data shipping. The redo log is continuously replayed on the secondary site immediately after arrival making this step superfluous during takeover. This mode does not require delta data shippings. Because of this the amount of data, which needs to be transferred to the secondary system is reduced.

logreplay_readaccess

This mode is required for replication to an Active/Active (read enabled) secondary system. It is similar to the logreplay operation mode regarding the continuous log shipping, the redo log replay on the secondary system, as well as the required initial full data shipping and the takeover.