Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Information in this document applies to any platform.
In a Data Guard environment primary database is open in read write mode and the standby database in read only mode for reporting purpose.
This document describes how to setup clients to connect to Data Guard databases (primary and standby) and configure automatic client failover such that in case there is role change due to switchover or failover, the client connections should still be valid i.e. the clients that need to connect to read only standby should always connect to the current standby irrespective of which database in the Data Guard configuration is currently in standby role and same for primary connections.
This goal is achieved via database services.
In 11gR2, we have the concept of role-based database services. For Data Guard environments running older release, this is achieved via a database startup trigger.
Note: Starting from 12cR1 (12.1), you can consider using Global Data Services to seamlessly manage client connections for dataguard or Golden Gate replicated database
Also check below technical brief for latest information on this topic:
Client Failover Best Practices for Highly Available Oracle Databases
http://www.oracle.com/technetwork/database/availability/client-failover-2280805.pdf
Application Continuity with Oracle Database12c Release 2
http://www.oracle.com/technetwork/database/database-cloud/private/application-continuity-wp-12c-1966213.pdf
In this Document