Linked Servers: Creating, Setting Options, and Querying with SQL Server
January 4, 2005[From InformIT]
Have you ever had to access data from either a non-SQL Server source or from a separate SQL Server database (either residing on the same instance or on a separate instance)? You might wish for a tool/utility to make that remote dataset appear as if it were in the same database as the one you're currently working on. Then joins, queries, and updates could be performed on them (like those operations are performed on the local objects in the database).
That wish is granted when you use a feature called linked servers in SQL Server.
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