Normalization of Single Level Nested Structure in Object-Relational Data Model

Object-Relational Data Model (ORM) has included various Object-Oriented (OO) conceptual implementations in a relational environment. One of the advances is the inclusion of ROW type feature to facilitate nested relation structure. In this paper, we propose a new normalization technique for relations with single nested structure using ROW type attribute. In our best knowledge, there is no work on the normalization of this attribute type. Yet, in database conceptual model we encounter many cases that can get benefit from single ROW type implementation. Our proposed normalization rules are based on the original purpose of removing anomalies in the database and use the theory of functional dependencies. The new normalization rules consider different scenarios that can create undesired dependencies in relations and propose the way to redesign the relations in order to avoid the database anomalies.