"A view is a virtual table whose contents are defined by a query...Unless indexed, a view does not exist as a stored set of data values in a database." *1
非索引视图
"Unlike permanent tables, a view has no physical representation of its data unless you create an index on it. Whenever you issue a query on a nonindexed view, SQL Server in practice has to access the underlying tables. Unless specified otherwise..." *1
因此,调用时计算非索引视图。
Indexed Views
"An indexed view is a view that has been materialized. This means the view definition has been computed and the resulting data stored just like a table." *2