How a warm standby for Oracle works

Figure 12-1 illustrates the normal operation of an example warm standby application.

Figure 12-1: Warm standby application

Figure 3-1 illustrates the normal operation of an example warm standby application where the client executes transactions in the active database. The Replication Server executes the transactions in the standby database and may also copy transactions to destination databases and remote Replication Servers.

In this warm standby application:

Client applications execute transactions in the active database.
The Replication Agent for the active database retrieves transactions from the transaction log and forwards them to Replication Server.
Replication Server executes the transactions in the standby database.
Replication Server may also copy transactions to destination databases and remote Replication Servers.

In a warm standby application, the active database and the standby database appear in the replication system as a connection from the Replication Server to a single logical database.

In many Replication Server applications:

A primary database is the source of data that is copied to other databases through the use of replication definitions and subscriptions.
A destination database receives data from the primary (source) database.

For detailed information about database connections, see Chapter 3, “Managing Warm Standby Applications” in the Replication Server Administration Guide Volume 2.