While database polling is certainly a sufficient way to learn about database changes, it is inherently fraught with inefficiency. In order to guarantee a timely processing of data, I have to set an aggressive polling window, which in turn means that there will be a measurable number of polling operations that return no results. In essence, the database acts as a passive store, which is constantly being harassed with "do you have anything yet" messages. Isn't there a better way?
Enter Query Notification which is a capability now supported by the WCF SQL Server adapter in concert with SQL Server 2008. Query notification is a means for the database server (through the use of SQL Server Service Broker) to communicate state changes to subscribers as they occur. So instead of asking for changes, the database tells you when a particular condition has been detected.
Yet again, we head to the Consume Adapter Service wizard to generate schemas. Like the previous demonstration...