SQL Server Notification Services Interview Preparation Guide
SQL Server Notification Services Interview Questions and Answers will guide us now that SQL Server Notification Services is based on SQL Server Technology, and sits atop the Microsoft .NET Framework. Notification Services offers a scalable server engine on which to run notification applications, with multi-server capability-providing flexibility and scalability for deploying applications. Learn SQL Server Notification by this SQL Server Notification Services Interview Questions and Answers guide15 SQL Notification Services Questions and Answers:
1 :: How does Notification Services Work?
Subscription data can be added using (SMO) Subscription Management Objects to Notification Services application. Events get populated to events table with the help of Event providers. When events are populated into events table, the generator wakes up and starts processing rules that are attached with subscriptions. The generator checks to see if any events match them. The generator starts creating notifications and fills the Notifications table, if matches are found. When notifications arrive in Notifications table, the distributor wakes up and starts processing each notification, formats it and delivers them using specified channel.
2 :: What are Notification services?
Notification Services are services which send notifications to the interested entities based on what they would like be notified on.
It is one of the features of the SQL Server.
It is one of the features of the SQL Server.
3 :: Explain architecture of SQL Server Notification services?
Notification Services consists four components
Subscription
Subscription data can be added using (SMO) Subscription Management Objects to Notification Services application.
Events
Events get populated to events table with the help of Event providers.
Generator
When events are populated into events table, the generator wakes up and starts processing rules that are attached with subscriptions. The generator checks to see if any events match them. The generator starts creating notifications and fills the Notifications table, if matches are found.
Delivery (notifications)
When notifications arrive in Notifications table, the distributor wakes up and starts processing each notification, formats it and delivers them using specified channel
Subscription
Subscription data can be added using (SMO) Subscription Management Objects to Notification Services application.
Events
Events get populated to events table with the help of Event providers.
Generator
When events are populated into events table, the generator wakes up and starts processing rules that are attached with subscriptions. The generator checks to see if any events match them. The generator starts creating notifications and fills the Notifications table, if matches are found.
Delivery (notifications)
When notifications arrive in Notifications table, the distributor wakes up and starts processing each notification, formats it and delivers them using specified channel
4 :: What are the basic components of Notification services?
The following terms are the components of Notification Service:
Event: an action that occurred affecting the specified data.
Subscriber: an entity that wants being notified on occurrence of an event.
Subscription: an act by which subscriber describes when and what he wants to be notified as.
Notification: a channel of communication
Event: an action that occurred affecting the specified data.
Subscriber: an entity that wants being notified on occurrence of an event.
Subscription: an act by which subscriber describes when and what he wants to be notified as.
Notification: a channel of communication
5 :: What are the restrictions applicable while creating views?
Views can be created referencing tables and views only in the current database.
A view name must not be the same as any table owned by that user.
You can build views on other views and on procedures that reference views.
Rules or DEFAULT definitions can't be associated with views.
Only INSTEAD OF triggers can be associated with views.
The query that defines the view cannot include the ORDER BY, COMPUTE, or COMPUTE BY clauses or the INTO keyword.
You cannot define full-text index definitions for views.
You cannot create temporary views
You cannot create views on temporary tables.
A view name must not be the same as any table owned by that user.
You can build views on other views and on procedures that reference views.
Rules or DEFAULT definitions can't be associated with views.
Only INSTEAD OF triggers can be associated with views.
The query that defines the view cannot include the ORDER BY, COMPUTE, or COMPUTE BY clauses or the INTO keyword.
You cannot define full-text index definitions for views.
You cannot create temporary views
You cannot create views on temporary tables.
6 :: Define Primary and Unique key?
Primary Key
► The column or columns of the table whose value uniquely identifies each row in the table is called primary key.
► You can define column as primary key using primary key constraint while you create table.
► When you define a column as primary key, a unique index is created which restricts duplicate data and fast access to data.
► A column defined as primary key doesn’t allow null value.
► By default, clustered index in created with the column having primary key.
Unique key
Unique key also ensures data uniqueness like primary key.
A column with unique key defined allows null value.
By default, it creates non-clustered index.
► The column or columns of the table whose value uniquely identifies each row in the table is called primary key.
► You can define column as primary key using primary key constraint while you create table.
► When you define a column as primary key, a unique index is created which restricts duplicate data and fast access to data.
► A column defined as primary key doesn’t allow null value.
► By default, clustered index in created with the column having primary key.
Unique key
Unique key also ensures data uniqueness like primary key.
A column with unique key defined allows null value.
By default, it creates non-clustered index.
7 :: Explain the difference between a primary key and a unique key?
► Both are defined to ensure unique row.
► Primary key creates a clustered index on the column by default.
► Unique creates a non-clustered index by default.
► Primary key doesn't allow NULLs, but unique key allows one NULL only.
► Primary key creates a clustered index on the column by default.
► Unique creates a non-clustered index by default.
► Primary key doesn't allow NULLs, but unique key allows one NULL only.
8 :: Define Distributed Query and Linked Server?
Distributed Query:
► Distributed Query is a query which can retrieve data from multiple data sources including distributed data.
► SQL Server supports distributed query through the use of OLE DB provider.
► OLE DB provider exposes data in the row sets which can be used in SQL Statement.
SQL Server can use distributed query in the SQL Statement using
Linked Server:
It is the virtual server that is created to access OLE DB data source.
It includes all the information needed to access OLE DB data source.
Linked server definition contains all the information needed to locate OLE DB data source.
You can join remote data and local data using Linked Server.
► Distributed Query is a query which can retrieve data from multiple data sources including distributed data.
► SQL Server supports distributed query through the use of OLE DB provider.
► OLE DB provider exposes data in the row sets which can be used in SQL Statement.
SQL Server can use distributed query in the SQL Statement using
Linked Server:
It is the virtual server that is created to access OLE DB data source.
It includes all the information needed to access OLE DB data source.
Linked server definition contains all the information needed to locate OLE DB data source.
You can join remote data and local data using Linked Server.
9 :: What is Distributed Queries?
Distributed queries can access data from different data sources. These sources can reside on the same server or a different server. This means that distributed queries can query multiple databases.
10 :: What is a linked server?
A linked server allows remote access. They have the ability to issue distributed queries, update, commands, and transactions across different data sources. A linked server has an OLE DB provider and data source.