Configuring FAN for OCI Clients

Oracle Call Interface (OCI) clients embed Fast Application Notification (FAN) at the driver level, so all clients can use it, regardless of the pooling solution.

Oracle recommends that both the server and the client are Oracle Database 19c or a later database release.

*Configuration for SQL*Plus and PHP*

Set notification for the service.
For PHP clients only, add the OCI8 extension setting oci8.events=On to the php.ini file.

Note:
If XML is present with events=-false, or if events are not specified, then FAN
is disabled. To maintain FAN with SQL*Plus and PHP when oraccess.xml is in use, set events=-true.
On the client side, enable FAN in XML with the database.

Configuration for Oracle Call Interface (OCI) Clients

Tell Oracle Call Interface (OCI) where to find ONS listeners.
The client installation includes ONS linked into the client library. With auto-configuration, ONS endpoints are automatically discovered from the TNS address. Oracle recommends this method. As with ODP.Net, you can also manually configure ONS using oraaccess.xml.
Enable FAN high availability events for the Oracle Call Interface connections.
To enable FAN you edit the OCI file XML to specify the global parameter events. This file is located in the path $ORACLE_HOME/network/admin.

For more information, see Oracle AI Database High Availability Overview and Best Practices
Enable FAN on the server for all Oracle Call Interface clients.

Note:
It is still
necessary to enable FAN on the database server for all OCI clients
(including SQL*Plus).