A keying method for a nested relational database management system
Zehra Meral Ozsoyoglu, Jun Wang · 2003
The authors discuss the keying methods that are proposed in the literature and introduce the external keying method which aims to restore the structure of tuples that is lost by unnesting a relation valued attribute in a nested relation. As opposed to the previous keying methods, it does not store the keying information within the relation instance which can be manipulated by relational algebra. Instead, the keying information is kept separately while it is generated, utilized, and manipulated.>