Microsoft SQL Server 2014 Unleashed

Indexed Views

You establish indexed views by creating a unique clustered index on the view itself, independent of the member tables that it references. The creation of this unique index transforms a view from an object that is virtual in nature to one that has physical storage associated with it. Like all other indexes, the index on a view takes up physical storage and creates some database overhead when rows change and the index must be updated to reflect that change. These factors must be considered but the performance benefits of the Indexed view can justify its creation.