A derived table results when you code a SELECT in the FROM clause of a SELECT or UPDATE statement.

Derived tables let you create or simplify complex queries. Useful in data warehousing applications, they provide a way to isolate complex portions of query syntax from the rest of a query.

Some complex queries cannot be implemented without using either pre-defined views or derived tables. The derived table behaves like an inline view, but is more concise and avoids having to define persistent objects that may be used for a single query only.

For details on derived tables, see the SQL Reference Guide.