Microsoft® SQL Server™ 2008 All-In-One Desk Reference For Dummies®

IV.6.3. Using Linked Servers

If you plan on querying an external data source more than a couple times, it makes sense to create a linked server. Creating the linked server does take some time and effort, but once created, you can refer to the data source on the remote server with a four-part name in Data Manipulation Language statements (such as SELECT, INSERT, UPDATE, and DELETE).

Creating and configuring a linked server is a two-step process:

1. Create the linked server.

   The linked server identifies the details of the remote server, such as the name of the server and the provider to use when connecting.

2. Create linked server logins.

   A login is a mapping between a login on the local server and a security account on the linked server.

It's easy to confuse the context of linked servers. You actually create a linked server object on a local server to connect to a remote server.

Let us say something obvious to avoid any confusion: When you create the linked server, you are not magically creating another physical server. Of course, that's ridiculous. Instead, the remote server already exists. By creating a linked server object in the local SQL Server, you are teaching SQL Server about the remote server.

Figure 6-2 shows the relationship between the local SQL Server, the remote server, and the linked server. It shows that you're creating the linked server object on the local SQL Server. The linked server object points to the remote server.

Figure IV.6-2. The local SQL Server, the linked ...