I'm a new comer to .Internet ... I'm trying to produce a background worker thread that may poll the database every 20s to discover if the data within the database has transformed or otherwise.

Do you know the steps needed to get this done? Is a good idea or must i use another thing?

Any tutorial/example is going to be appreciated

Polling a database could be a large performance problem. For those who have treatments for the service that updates the database, I recommend giving a celebration from that plan to any client/service that could be thinking about understanding the db has changes for any specific record.

Otherwise, you are able to consider utilizing a background thread. To achieve that, simply produce a thread using System.Threading.Thread. If you're hooking up to some MS SQL Server database, you should use System.Data.SqlClient classes.