Views
A view can be thought of as a virtual table. Only the definition for the view is stored, not the data. A table on which a view operates is called a base table.
A view definition can encompass 1 to 31 base tables. It can involve multiple tables joined together by their common columns using a where qualification.
A view can be created on other views or on physical database tables, including secondary indexes.
Primary uses for views include:
• Providing security by limiting access to specific columns in selected tables, without compromising database design
• Simplifying a commonly used query
• Defining reports
Because a view is a device designed primarily for selecting data, all selects on views are fully supported. Simply use a view name in place of a table name in the SELECT statement. Updating views is also supported (see Updates on Views), but updating a database by means of a view is not recommended.