Solving the Implication Problem for XML Functional Dependencies with Properties

Hartmann, Sven; Link, Sebastian; Trinh, Thu

doi:10.1007/978-3-642-13824-9_14

Cited by 19 publications

(9 citation statements)

References 15 publications

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“…Armstrong's Axioms for functional dependencies in relational databasesand proved that they are sound and complete (Yan and Ma, 2011;Shahriar and Liu, 2009;Hartmann et al, 2010). Compared to the relational counterpart, however, the task of finding such a set of inference rules for XFDs is much more difficult.…”

Section: Resultsmentioning

confidence: 99%

“…Functional dependencies for XML: First, we should emphasize that semantic constraints (Shahriar and Liu, 2009;Hartmann et al, 2010) are not part of XML specifications. They can be regarded as the extension of XML schema to make XML documents more significant.…”

Section: Value Equality and Node Identitymentioning

confidence: 99%

“…But the problem with XML is that it is only syntax and does not carry the semantics of the data. Recently, keys (Hartmann et al, 2008), foreign keys (Hartmann et al, 2010) and functional dependencies (Shahriar and Liu, 2009) have been proposed to capture semantic constraints and various aspects of these proposals have found their way into XML-Data and XML Schema. Among these proposals, functional dependencies for XML are important to capture the semantics of XML data.…”

Section: Introductionmentioning

confidence: 99%

“…The second constraint is an example of a functional dependency (Hartmann et al, 2010;Shahriar and Liu, 2009) and cannot be expressed as a key constraint. Even though attempts to define functional dependencies have been made by several groups of researcher, they have different expressive power and some cannot express the constraint that the student number determines the student name for all Student nodes in the entire document as shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

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Normalized Relational Storage for Extensible Markup Language (XML) Schema

Ahmad

Samad

2011

Journal of Computer Science

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Problem statement:The use of XML as the common formats for representing, exchanging, storing, integrating and accessing data posses many new challenges to database systems. Most of application data are stored in relational databases due to its popularity and rich development experiences over it. Therefore, how to provide a proper mapping approach from XML model to relational model become the major research problems. Current techniques for managing XML in relational technology consider only the structure of an XML document and ignore its semantics as expressed by keys and functional dependencies. Approach: In this study we present an algorithm for generating an optimal design for XML in relational setting. The algorithm is based on computing a set of minimum covers for all functional dependencies on a universal relation when given XML Functional Dependencies (XFDs) and the schema information. However we need to deal with the hierarchical nature of XML and to define XFDs in this structure. Results: We show that our algorithm is efficient in terms of reducing data redundancy and preserving semantic expression. Conclusion/Recommendations: Being able to infer XML functional dependencies constraints to relational views of XML data is a first step towards establishing a connection between XML and its relational representation at the semantic level.

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Section: Resultsmentioning

confidence: 99%

Section: Value Equality and Node Identitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Normalized Relational Storage for Extensible Markup Language (XML) Schema

Ahmad

Samad

2011

Journal of Computer Science

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“…While constraints such as keys [16,32,34] and functional dependencies [2,29,38,59,61] have received considerable attention, research on the class of multivalued dependencies has only been preliminary [53,60].…”

Section: Discussionmentioning

confidence: 99%

Appropriate inferences of data dependencies in relational databases

Biskup

Link

2011

Ann Math Artif Intell

Self Cite

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We study inference systems for the combined class of functional and full hierarchical dependencies in relational databases. Two notions of implication are considered: the original notion in which a dependency is implied by a given set of dependencies and the underlying set of attributes, and the alternative notion in which a dependency is implied by a given set of dependencies alone. The first main result establishes a finite axiomatisation for the original notion of implication which clarifies the role of the complementation rule in the combined setting. In fact, we identify inference systems that are appropriate in the following sense: full hierarchical dependencies can be inferred without use of the complementation rule at all or with a single application of the complementation rule at the final step of the inference only; and functional dependencies can be inferred without any application of the complementation rule. The second main result establishes a finite axiomatisation for the alternative notion of implication. We further show how inferences of full hierarchical dependencies can be simulated by inferences of multivalued dependencies, and vice versa. This enables us to apply both of our main results to the combined class of functional and multivalued dependencies. Furthermore, we establish a novel axiomatisation for the class of non-trivial functional dependencies.

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