Object normal forms and dependency constraints for object-oriented schemata

Tari, Zahir; Stokes, John; Spaccapietra, Stefano

doi:10.1145/278245.278247

Cited by 67 publications

(27 citation statements)

References 16 publications

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“…In an ORDB, a table may not be in the first normal form of the relational data model, and a table can be nested in another table. Various nested normal forms are studied as an extension of traditional flat normal forms in the relational data model area [26][27][28], but these extensions are based on the relational algebra and relational data model. Similar to the comparison in Table I, the RSM is different from the ORDB in foundation, managed object, data model, normalization basis, operation feature, and exchange basis.…”

Section: Comparison Between Rsm Multi-dimensional Data Model and Objmentioning

confidence: 99%

Resource Space Grid: model, method and platform

Zhuge

2004

Concurrency and Computation

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SUMMARYA Resource Space Grid is a virtual Grid that aims at effectively sharing, using and managing versatile resources across the Internet. The kernel of the Resource Space Grid includes a Resource Space Model (RSM) and a uniform Resource Using Mechanism (RUM). This paper presents the Resource Space Grid's core scientific issues and methodology, architecture, model and theory, design criteria and method, and practice. A normal form theory is proposed to normalize the resource space-a coordinate system for uniformly specifying and organizing resources. The RUM provides not only the end-users with an operable resource browser to operate resources using the built-in Resource Operation Language (ROL), but also the application developers with the ROL-based programming environment. The prototype platform based on the proposed model and method has been implemented and used for sharing and managing resources in distributed research teams. Operations on Resource Spaces can constitute the virtual communities of Resource Space Grids-a platform independent resource sharing environment.

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Section: Comparison Between Rsm Multi-dimensional Data Model and Objmentioning

confidence: 99%

Resource Space Grid: model, method and platform

Zhuge

2004

Concurrency and Computation

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“…Ansätze wie etwa [1,12,13,20] haben bereits verschiedene Vorarbeiten geleistet, um beispielsweise spezielle Formen der Datenredundanz oder vonÄnderungsanomalien zu identifizieren und geeignete Normalformen zu finden, um diese Probleme zu beseitigen. In der Regel werden dazu die aus dem relationalen Bereich bekannten funktionalen und mehrwertigen Abhängigkeiten geeignet erweitert und darauf basierend Normalformen definiert.…”

Section: Andere Ansätzeunclassified

“…Der Ansatz von Tari et al [20] kann unter den zuvor genannten als der wohl weitreichendste angesehen werden.…”

Section: Andere Ansätzeunclassified

Restrukturierung objektorientierter Datenbankschemata mittels formaler Begriffsanalyse

Schmitt¹,

Conrad²

1999

Informatik Forsch Entw

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Zusammenfassung. Eine Restrukturierung eines gegebenen Datenbankschemas kann aus unterschiedlichen Gründen notwendig werden. So kann dadurch z.B. die Verständlichkeit des Schemas verbessert werden. Im Bereich der relationalen Datenbanken steht die Normalisierungstheorie zur Verfügung, um z.B. Redundanz zu vermeiden. Der Normalisierung liegt dabei ein Begriff derÄquivalenz von Datenbankschemata zugrunde. Im Bereich der objektorientierten Datenbanken gibt es bislang kaum vergleichbare Ansätze. In diesem Beitrag präsentieren wir daher einen Ansatz, mit dem Klassenhierarchien in objektorientierten Datenbankschemata in eine ,,normalisierte" Form transformiert werden können. Dazu muß zunächst eine extensionale Analyse durchgeführt werden, die die notwendigen Informationenüber extensionale Beziehungen zwischen den gegebenen Klassen liefert. Anschließend wenden wir Konzepte der formalen Begriffsanalyse an, um eine ,,normalisierte" Klassenhierarchie abzuleiten.Abstract. Different reasons may require to restructure an existing database schema. For instance, restructuring can improve the comprehensibility of a schema. For relational databases there is the relational normalization theory which provides a means of avoiding redundant storage of data. Normalization is based on a notion of equivalence for database schemata. At the time being, there are only very few comparable approaches to normalizing object-oriented databases. In this article we present an approach to transforming class hierarchies in object-oriented database schemata into a "normal form". For this transformation we first have to perform an extensional analysis which provides the necessary information about extensional relationships among the classes in a given schema. Then, we apply the framework of formal concept analysis in order to derive a "normalized" class hierarchy.Diese Arbeit wurde teilweise vom Land Sachsen-Anhalt unter FKZ 1987A/2527R unterstützt.

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“…First, so-called semantic data models have been developed [29,60,94], which were originally just meant to be used as design aids, as application semantics was assumed to be easier captured by these models [10,30,96]. Later on some of these models, especially the nested relational model [64,81], object-oriented and object-relational models [12,42,44,89,90] have become interesting as data models in their own right and some dependency and normalisation theory has been carried over to these advanced data models [48Y50, 55,57,69,77,79,80,84,85,92,95]. A comparison of the various normal forms for the nested relational data model proposed in [77,79,80,84,85] can be found in [76].…”

Section: Introductionmentioning

confidence: 99%

Functional and multivalued dependencies in nested databases generated by record and list constructor

Hartmann

Link

Schewe

2006

Ann Math Artif Intell

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The impact of the list constructor on two important classes of relational dependencies is investigated. Lists represent an inevitable data structure whenever order matters and data is allowed to occur repeatedly. The list constructor is therefore supported by many advanced data models such as genomic sequence, deductive and object-oriented data models including XML. The article proposes finite axiomatisations of functional, multivalued and both functional and multivalued dependencies in nested databases supporting record and list constructor. In order to capture different data models at a time, an abstract algebraic approach based on nested attributes is taken. The presence of the list constructor calls for a new inference rule which allows to infer non-trivial functional dependencies from multivalued dependencies. Further differences to the relational theory become apparent when the independence of the inference rules is investigated. The extension of the relational theory to nested databases allows to specify more real-world constraints and increases therefore the number of application domains.

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Object normal forms and dependency constraints for object-oriented schemata

Cited by 67 publications

References 16 publications

Resource Space Grid: model, method and platform

Resource Space Grid: model, method and platform

Restrukturierung objektorientierter Datenbankschemata mittels formaler Begriffsanalyse

Functional and multivalued dependencies in nested databases generated by record and list constructor

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