Server 2000's powerful new support for indexed views promises to make your life easier while making your applications and queries run faster. Sound too good to be true? Indexed views let you precompute all sorts of joins, aggregations, and computations so that you don't have to write such conditions into every query. And Microsoft is reporting gains of 10 to 100 times in the performance of applications and queries that access indexed views instead of base tables. Although Oracle supports a similar feature called materialized views, SQL Server's new indexed views go far beyond what the competition offers.
Please checkout in http://sqlmag.com/database-performance-tuning/introducing-indexed-views