Rox,

Currently SQL Server doesn't persist views. When you create a view, the view definition (which is a query) is stored within the database. When you access the view, by referring to it in the FROM clause of a query, SQL Server merges the query that makes up the view and your query into one "mutant" query and then processes it.

A materialized view has a physical presence or persistence within the database. You can think of it as a physical table but the implementation is left up to the vendor. The database engine has a mechanism to keep the view up to date with the data in the base tables.

Currently Oracle supports materialized view. It's the reason that they were able to score so high on that benchmark. That's when Oracle offered the Million dollar challenge.

-Mike