An iterator function in the FROM clause of a SELECT statement

In addition to tables, an iterator function can be specified as a source for a SELECT statement. This means you can query the return result set of an iterator UDR using a table interface. Therefore, you can manipulate the iterator result set in a number of ways, such as by using the WHERE clause to filter the result set; by joining the UDR result set with other table scans; by running GROUP BY, aggregation, and ORDER BY operations, and so on.