Question

We have an ETL package that writes data to the SQL Server. Data is displayed on ASP.Net web pages. Occasionally ETL may recognize an alarm condition (it is also written to the database). In this case UI must be notified immediately. What is the appropriate technology to push something from either ETL or SQL Server to ASP.Net UI?
StreamInsight appears to be an overkill. Cache Dependency doesn’t seem to include a way to push events to the client. What is your recommendation?

Answer 1

You can make use of Query Notifications in SQL Server. Query notifications allow applications to be notified when data has changed. This feature is particularly useful for applications that provide a cache of information from a database, such as a Web application, and need to be notified when the source data is changed.
For more information see this link msdn link

Hope it helps !!

EDIT :
You can use the SqlCacheDependency class in your case. The SqlCacheDependency makes use of the SqlDependency to remove data from the cache when a dependency changes. It derives from the CacheDependency base class, which is one of the parameters used when inserting an item into the cache.
When a SqlCacheDependency is created with a database and table name, it will monitor the table for changes. Monitoring the table is done with the polling features that are available with SQL Server. The way polling works is by attaching a trigger to the table to be monitored that is fired with each insert, update, and delete statement. The trigger increments a number in a status table for this source table to indicate that the table has been changed. When a table is being monitored, this status table is polled for that number to check whether it has changed.
You can get a lot of example of implementing this on google. One such is presented here