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Relational data model

The relational model is a data model with a thorough mathematical foundation. An attribute is a named set of atomic values, the domain. A relation table is a subset of the cross-product of the relation attributes.

The relational data model separates the logical data definition from physical storage.

Two data manipulation languages have been developed for the relational data model:

The relational data model makes no assumptions about the relationships between entities. In general, an entity is mapped to a relation table, with the properties of an entity described through the relation attributes. Meaningful relationships between entities are expressed through relational algebra operations or calculus expressions. Hence, complex relationships between entities can be expressed, with the notable expression of recursive relationships.

EAGLES SWLG SoftEdition, May 1997. Get the book...