When you set the save_interval for a physical or logical connection between a Replication Server and a data server and database, you allow Replication Server to save transactions in the DSI queue. You can restore the backlogged transactions using the sysadmin restore_dsi_saved_segments command. Refer to the Replication Server Reference Manual for more information.
You can use these saved transactions to resynchronize a database after it has been loaded to a previous state from transaction dumps and database dumps.
For example, in Figure 7-1, if the replicate data server SYDNEY_DS that is connected to Replication Server SYDNEY_RS experiences a failure, it can obtain the messages saved in the DSI queue at SYDNEY_RS to resynchronize the replicate database after it has been restored.
You can also use the save_interval for setting up a warm standby of a database that holds some replicate data or one that receives applied functions.
To set the save_interval for a database connection, execute the alter connection command at the Replication Server. For example, here is the command to set Replication Server SYDNEY_RS to save for one hour any messages destined for its replicate data server SYDNEY_DS.
alter connection to SYDNEY_DS.pubs2 set save_interval to '60'
By default, the save_interval is set to 0 (minutes).
You can also configure the save intervals for the DSI queue and the materialization queue for a logical connection. See “Configuring logical connection save intervals” for details.
