Database modeling and design (3rd ed.)
Database modeling and design (3rd ed.)
An introduction to database systems (7th ed.)
An introduction to database systems (7th ed.)
The theory of joins in relational databases
ACM Transactions on Database Systems (TODS)
Multivalued dependencies and a new normal form for relational databases
ACM Transactions on Database Systems (TODS)
Database (2nd ed.): principles, programming, and performance
Database (2nd ed.): principles, programming, and performance
Information Modeling and Relational Databases
Information Modeling and Relational Databases
How to Avoid Redundant Object-References
OTM '08 Proceedings of the OTM Confederated International Workshops and Posters on On the Move to Meaningful Internet Systems: 2008 Workshops: ADI, AWeSoMe, COMBEK, EI2N, IWSSA, MONET, OnToContent + QSI, ORM, PerSys, RDDS, SEMELS, and SWWS
Reduction Transformations in ORM
OTM'07 Proceedings of the 2007 OTM confederated international conference on On the move to meaningful internet systems - Volume Part I
Object-Role Modeling: Principles and Benefits
International Journal of Information System Modeling and Design
Roles in ORM: a suggested semantics
OTM'11 Proceedings of the 2011th Confederated international conference on On the move to meaningful internet systems
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This paper contrasts two different approaches to designing relational databases that are free of redundancy. The Object-Role Modeling ORM approach captures semantics in terms of atomic elementary or existential fact types, before grouping the fact types into relation schemes. Normalization by decomposition instead focuses on "non0loss decomposition" to various, and progressively more refined, "normal forms". Traditionally, non0loss decomposition of a relation requires decomposition into smaller relations that, upon natural join, yield the exact original population. Non-loss decomposition of a table scheme or relation variable requires that the decomposition of all possible populations of the relation scheme is reversible in this way. This paper shows that the dependency requirement for "all possible populations" is too restrictive for definitions of multi-valued and join dependencies over relation schemes. By exploiting ORM modeling heuristics, the authors offer new definitions of these data dependencies and non-loss decomposition, to enable these concepts to be addressed at a truly semantic level.