RaiseError in SQL Server
mmm. How many of us thought about giving a progress to the client as a feed back mechanism for a long running SQL call. Read the following blog where Jens used RaiseError event differently from inside the stored procedure to give a feedback to client application on the progress.
http://blogs.msdn.com/jenss/archive/2009/05/11/getting-feedback-progress-from-batches-and-stored-procedures.aspx