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Data Model: Overview Relations Links Other Relations Semantics | Previous Next |
The Links concept of the URR The entries in the Links relation connect a source entry and a target entry in two different relations or in the same relation. This concept is a novel and rather powerful way of capturing interconnectivity. The URR link concept is different from the standard links provided in the context of a relational database. There, links are defined between two relations using the attributes (columns of the relation in tabular format). For example, the second attribute (column) of one relation could be linked to the third attribute (column) in a second relation. To be more specific, company addresses collected in one relation could be linked to persons collected in another relation through the company identification. However, no specific information pertaining to the link between a specific person and a specific company can easily be captured with this concept. Considering the relations as tables, the URR link concept links a specific row in one relation to a specific row in the same or another table. A link between entry A and entry B can be described through a number of attributes, including link value and link implementation status. The Links relation by itself is a relation, which is not linked as a relation to any of the other relations. |