What is a Data Model?
– A data model of high level in any functional area or business can be considered to be an abstract model.
– It helps in the documentation and organization of the business data in order to establish a communication link among the technical and functional people.
– It also represents the data that is needed and created for the business processes.
– A usual data model establishes a communication link between the members of a team.
– It also serves as a plan for the application development and lays primary specifications up on the storage and accessing the data.
– A data model is a way finding tool for IT as well as business professionals.
– It makes use of text and a set of symbols for giving an explanation on a real information subset so as to improving the existing communication in the organization and thereby leading to an increase in the stability and flexibility of the application environment.
– The structure of data is determined explicitly by the data model.
– Below mentioned are the typical application areas of the data models:
1. Data base models
2. Designing of the information systems
– A data modeling language is used to make specifications in a data model.
– The importance of the data model to the applications is realized through two key benefits namely precision and communication.
– It actually acts as a medium through which the members of the project development team who come from a number of different backgrounds and cultures to communicate.
– This explains the communication benefit and by precision we mean the interpretation of the terms and rules of a data model in one way and in an unambiguous way.
– Many refer to the data model as a data structure under the programming language context.
– Function models very well complement the data models under the enterprise model context.
– There are two meanings related to any data model as stated below:
1. A data model instance: It is concerned with the application of a data model theory for the creation of a data model for an application.
2. A data model theory: It is concerned with describing the structure and access to the data.
Components of Data Model Theory
There are 3 components of a data model theory as discussed below:
1. The structural part: This component consists of the data structures which can be used for creating the data bases that represent the objects or entities as data base models them.
2. The integrity part: This component consists of the rules that govern the constraints which are placed up on the data structures as a means for ensuring the structural integrity.
3. The manipulation part: This component consists of the operators whose application is for the data structures for querying and updating the data that is contained in the data base.
For the relational model the structural part is laid on the concept of the mathematical relation but slightly modified. The first order logic is used to express the integrity part and the below mentioned three things are used to express the manipulation part:
1. Relational algebra
2. Tuple calculus and
3. Domain calculus.
Where is Data Model Theory implemented?
– Data model theory is applied in order to create an instance of a data model for solving some of the business enterprise requirements.
– A semantic logical data model is used to capture the business requirements which is then transformed in to a physical data model instance which is then further used generating a physical data base.
– A data modeling tool might be used by a data modeler for developing an entity – relationship model for the corporate data repository concerning the business enterprise.
– Next, for generating a relational data base this model is turned in to a relational model.
– One of the common data modeling data structures called patterns which have a frequent occurrence in most of the data models.
– The unstructured data is not typically described.