What is query notifications?

What is query notifications?

Built upon the Service Broker infrastructure, 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.

What is query notifications in SQL Server?

Query notifications allow you to request notification within a specified time-out period when the underlying data of a query changes. The request for notification specifies the notification options, which include the service name, message text, and time-out value to the server.

What is QRCN?

If a query is registered for query result change notification (QRCN), the database notifies the application whenever a transaction changes the result of the query and commits.

What are different types of dependency?

Dependency types

• goal dependency.
• task dependency.
• resource dependency.
• softgoal dependency.

Which of the following packages will you use when you want an application to be notified whenever the value of interest in the database are changed?

DBMS_ALERT supports asynchronous notification of database events (alerts). By appropriate use of this package and database triggers, an application can notify itself whenever values of interest in the database are changed.

Do you need to enable query notifications in SQL Server?

Applications that consume query notifications have a common set of requirements. Your data source must be correctly configured to support SQL query notifications and the user must have the correct client-side and server-side permissions. To use query notifications, you must: Enable query notifications for your database.

When to use query notifications in ADO.NET?

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. There are three ways you can implement query notifications using ADO.NET:

How to use.net framework for SQL server notifications?

In most cases, this is the simplest and most effective way to leverage SQL Server notifications capability by managed client applications using the .NET Framework Data Provider for SQL Server. In addition, Web applications built using ASP.NET 2.0 or later can use the SqlCacheDependency helper classes.

How are notifications delivered in SQL Server Native Client?

The request for notification specifies the notification options, which include the service name, message text, and time-out value to the server. Notifications are delivered through a Service Broker queue that applications may poll for available notifications.