Microsoft® SQL Server™ 2000 Unleashed, Second Edition

Views and Query Performance

Views typically do not add any additional overhead to query performance. A SELECT statement against a view is just as fast as the underlying query used to define the view. When a view is combined with other search arguments or join conditions in a query, the query optimizer combines the source of the view and the SQL statement into a single execution plan. Since it doesn't generate separate query plans for the view and the SQL statement, the view result doesn't have to be materialized first before it can resolve the rest of the query. Consider the first query shown in Listing 27.11 that references the High_Sales_View view, which was defined in Listing 27.6. The query referencing the view generates the same execution ...