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Title:A normal form for XML documents
Authors: Leonid Libkin ; Marcelo Arenas
Date: 2004
Publication Title:ACM Transactions on Database Systems
Publication Type:Journal Article Publication Status:Published
Volume No:29 Page Nos:195-232
This paper takes a first step towards the design and normalization theory for XML documents. We show that, like relational databases, XML documents may contain redundant information, and may be prone to update anomalies. Furthermore, such problems are caused by certain functional dependencies among paths in the document. Our goal is to find a way of converting an arbitrary DTD into a well-designed one, that avoids these problems. We first introduce the concept of a functional dependency for XML, and define its semantics via a relational representation of XML. We then define an XML normal form, XNF, that avoids update anomalies and redundancies. We study its properties and show that it generalizes BCNF and a normal form for nested relations when those are appropriately coded as XML documents. Finally, we present a lossless algorithm for converting any DTD into one in XNF.
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Bibtex format
author = { Leonid Libkin and Marcelo Arenas },
title = {A normal form for XML documents},
journal = {ACM Transactions on Database Systems},
publisher = {ACM},
year = 2004,
volume = {29},
pages = {195-232},
doi = {10.1145/974750.974757},
url = {},

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