Restrictions on Views and Detail Tables

There are certain restrictions on views and their detail tables.

• When a view is referenced in the FROM clause of a SELECT statement, its name is replaced by its definition as a derived table during SQL compilation. The content of the derived table is said to be materialized, but this materialization is temporary and only exists for the duration of the SQL statement. For example, if both the view and the referencing select specify aggregates, the view is materialized before its result can be joined with other tables of the select.

• A view cannot be dropped with a DROP TABLE statement. You must use the DROP VIEW statement.

• A view cannot be altered with an ALTER TABLE statement.

• Referencing a view can fail due to dropped or altered detail tables.