Information AboutData Model |
| CATEGORIES ABOUT DATA MODEL | |
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A data model is an abstract model that describes how Data is represented and used. The term data model has two generally accepted meanings: # A data model ''theory'' i.e. a formal description of how data may be structured and used. See also Database Model # A data model ''instance'' i.e. applying a data model ''theory'' to create a practical data model ''instance'' for some particular application. See Data Modeling . DATA MODEL THEORY A ''data model theory'' has three main components:
For example, in the Relational Model , the structural part is based on a modified concept of the Mathematical Relation ; the integrity part is expressed in First-order Logic and the manipulation part is expressed using the Relational Algebra , Tuple Calculus and Domain Calculus . DATA MODEL INSTANCE Data Modeling is the process of creating a ''data model instance'' by applying a ''data model theory''. This is typically done to solve some business enterprise requirement. Business requirements are normally captured by a semantic Logical Data Model . This is transformed into a physical ''data model instance'' from which is generated a physical Database . For more information on the tools and techniques of data modelling, see Data Modelling . For example, a Data Modeler may use a data modeling tool to create an ERD of the Corporate Data Repository of some business enterprise. This model is transformed into a Relational Model , which in turn generates a Relational Database . EXTERNAL LINKS
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