Alerter Process

To exchange information between sessions, an alerter on an Oracle database uses the Oracle AQ package while an alerter on a Microsoft SQL Server 2005 or higher database uses the Service Broker component. In this way, two or more sessions in the same database instance can synchronously communicate with each other.

Note: Microsoft SQL Server 2005 or higher is shortened as Microsoft SQL Server hereafter.

The following figure shows the alerter process on an Oracle or Microsoft SQL Server database.

As shown in the figure, when a source table is updated with data and the commit_and_notify stored procedure is executed, a trigger copies the data to the publishing table and notifies Oracle AQ or Microsoft SQL Server Service Broker that the publishing table has changed.

The alerter receives the notification from Oracle AQ or Microsoft SQL Server Service Broker and sends a message to the adapter to inform that a publishing table has changed. The adapter then polls all its configured publishing tables for the new data and sends it on a subject to the TIBCO transport.

If multiple publishing tables exist under the same database account, you can use the commit_and_notify_table stored procedure to specify that only a particular table is checked by the adapter. This prevents the adapter from needlessly checking all its publishing tables for updates when only one table has been updated with new data. This notification can be sent to one or more adapter configurations.