As XML becomes widely used, dealing with redundancies in XML data has become an increasingly important issue. Redundantly stored information can lead not just to a higher data storage cost, but also to increased costs for data transfer and data manipulation, such data redundancies can lead to potential update anomalies. One way to avoid data redundancies is to employ good schema design based on known functional dependencies. This paper presents a graphical approach to model XML documents based on a Data Type Documentation called Graphical Notations-Data Type Documentation (GN-DTD). GN-DTD allows us to capture syntax and semantic of XML documents in a simple way but precise. Using various notations, the important features of XML documents such as elements, attributes, relationship, hierarchical structure, cardinality, sequence and disjunction between elements or attribute are visualize clearly at the schema level.
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