Advanced capabilities of the outer join

This paper demonstrates that the modeling of complex data structures can be performed easily and naturally in SQL using the direct outer join operation as defined in the proposed ISO-ANSI SQL2 standard. This paper goes on to demonstrate four advanced capabilities that can be implemented by SQL vendors utilizing the data modeling ability of the outer join. These capabilities are: powerful optimization techniques that can dynamically shorten the access path length; intelligent join view updates that utilize the semantics in the data structure being modeled; direct disparate heterogeneous database access that is transparent and efficient; and automatic conversion of multi-table structures into nested relations allowing for more powerful SQL operations.