Collections of Objects in SQL3

SQL3 generalizes the relational model into an object model offering abstract data types, multiple inheritance, and dynamic polymorphism. Tables may then contain collections (multisets) of objects, and sets and lists are defined as closely related collection types. By specifying an SQL-Table type template to correspond to the existing Table concept, it is possible to treat sets and lists as subtypes of tables that inherit the behavior (and SQL syntax) for tables, while adding their own specializations. The SQL set-at-a-time data manipulation kanguage can then be applied to collections of objects, i.e. tables in which each row is an object. 1