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Object Relationship Attribute Data Model for Semi-structured Data

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Synonyms

ORA-SS data model; ORA-SS schema diagram

Definition

When a database schema is designed, a data model is initially used to model the real world constraints that are taken into account in the design of the schema. For semi-structured database design, it is necessary to capture the following constraints: object classes, n-ary relationship types, attributes of object classes, attributes of relationship types, cardinality, participation and uniqueness constraints, ordering, irregular and heterogeneous structures, for both data- and document-centric data.

Key Points

The ORA-SS (Object-Relationship-Attribute Data Model for Semi-structured Data) data model was designed [1] specifically to capture the constraints that are necessary for designing semi-structured databases, for normalization of schemas, and for defining views.

Figure 1models the scenario where there is a department, with a name and many courses. A course has a unique code, a title, and many students, and a student has...

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Recommended Reading

  1. Ling T.W., Lee M.L., and Dobbie G. Semi-structured Database Design. Springer, Berlin Heidelberg New York, 2005.

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© 2009 Springer Science+Business Media, LLC

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Dobbie, G., Ling, T.W. (2009). Object Relationship Attribute Data Model for Semi-structured Data. In: LIU, L., ÖZSU, M.T. (eds) Encyclopedia of Database Systems. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-39940-9_5042

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