What is Linked Servers or Database Links?

                  Don't be confused by the two terms; both are the same. In SQL Server it is called a Linked Server whereas in Oracle it's DBLinks (Database Links).

Linked Servers allows you to connect to other database instances on the same server or on another machine or remote servers. 

It allows SQL Server to execute SQL scripts against OLE DB data sources on remote servers using OLE DB providers. 

The remote servers can be SQL Server, Oracle etc. which means those databases tht support OLE DB can be used for linking servers.

               After setting up the Linked Servers we can easily access the other server tables, procedures etc. 

After establishing a connection we can even do CRUD operations. 

The advantage is about security; its works on Windows as well as SQL Server Authentications.

How to find information about existing Linked Servers?

We can get Linked Server basic information by executing the following stored procedure created in the master database or default system.

exec sp_linkedservers

  OR

using select * from sys.servers will return more information about servers.

 

 This will create a Linked Server; we can view this from Management Studio.