Motivation for Nesting Nesting of data is useful in data transfer Example:elements representing item nested within an itemlist element Nesting is not supported,or discouraged,in relational databases With multiple orders,customer name and address are stored redundantly normalization replaces nested structures in each order by foreign key into table storing customer name and address information Nesting is supported in object-relational databases But nesting is appropriate when transferring data External application does not have direct access to data referenced by a foreign key Database System Concepts-6th Edition 23.10 @Silberschatz,Korth and SudarshanDatabase System Concepts - 6 23.10 ©Silberschatz, Korth and Sudarshan th Edition Motivation for Nesting Nesting of data is useful in data transfer Example: elements representing item nested within an itemlist element Nesting is not supported, or discouraged, in relational databases With multiple orders, customer name and address are stored redundantly normalization replaces nested structures in each order by foreign key into table storing customer name and address information Nesting is supported in object-relational databases But nesting is appropriate when transferring data External application does not have direct access to data referenced by a foreign key