Combining data from
one or more tables through a standard view lets you satisfy most of the
benefits of using views. These include focusing on specific data and
simplifying data manipulation. These benefits are described in more detail in Scenarios for Using Views.
An indexed view is a
view that has been materialized. This means it has been computed and stored.
You index a view by creating a unique clustered index on it. Indexed views
dramatically improve the performance of some types of queries. Indexed views
work best for queries that aggregate many rows. They are not well-suited for
underlying data sets that are frequently updated. For more information, see Designing Indexed Views.
A partitioned view
joins horizontally partitioned data from a set of member tables across one or
more servers. This makes the data appear as if from one table. A view that
joins member tables on the same instance of SQL Server is a local partitioned
view.
When a view joins data
from tables across servers, it is a distributed partitioned view. Distributed
partitioned views are used to implement a federation of database servers. A
federation is a group of servers administered independently, but which cooperate
to share the processing load of a system. Forming a federation of database
servers by partitioning data is the mechanism that lets you scale out a set of
servers to support the processing requirements of large, multitiered Web sites.
For more information, see Creating Partitioned Views.
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