Def: Data Model

As per today's discussion, we need to define Data Model.  Below is a start,
please review and rip it apart for better
comprehension.........................

Data Model WC The product of the database design process which aims to to
identify and organize the required data logically and physically. A data
model says what information is to be contained in a database, how the
information will be used, and how the items in the database will be related
to each other. For example, a data model might specify that a customer is
represented by a customer name and credit card number and a product as a
product code and price, and that there is a one-to-many relation between a
customer and a product. It can be difficult to change a database layout once
code has been written and data inserted. A well thought-out data model
reduces the need for such changes. Data modelling enhances application
maintainability and future systems may re-use parts of existing models,
which should lower development costs. A data modelling language is a
mathematical formalism with a notation for describing data structures and a
set of operations used to manipulate and validate that data. One of the most
widely used methods for developing data models is the entity-relationship
model. The relational model is the most widely used type of data model.
Another example is NIAM. 


Katie Haritos-Shea
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