Database Design Using Data Modeling – Conceptual, Logical And Physical
In this article, we will look at the actual process involved in designing a database by using the concept of Data Modeling. We will also look at the various models involved in creating a database namely the Conceptual data model, Logical data model and Physical data model.
What is Data Modeling?
Data Modeling is the process of defining and analyzing the data requirements of the business. It solves the purpose of outlining of the structure of the new software and the data flow between the different elements that make up the structure. Generally, the Data Modeling is done during the analysis and design phases of a project to make sure that the requirements of the application are understood correctly with the scope of correction, should there be any errors.
How is Data Modeling done?
Data Modeling is generally achieved by making use of diagrams, symbols, and text to represent the flow of data. These set of diagrams, symbols, text, etc. convey the direction in which the data flows and how the data is interlinked within the application.
Benefits of Data Modeling:
- Data Modeling helps visualize the flow of data and the connection across different pieces of data, across the application. This allows the owners of the application (typically called stakeholders) to actually identify problematic data correlation, functional errors and they can have these issues fixed before any actual programming code is written. This helps make new crucial decisions effectively and make amendments to the existing ones without costing a financial burden on the application owners.
- It helps identify data flow across the application, the link between the various processes, entities and their corresponding relationships.
Levels of Data Modeling:
There are three levels of Data Modeling, namely:
- Conceptual Data Model or Conceptual Database Design
- Logical Data Model or Logical Database Design
- Physical Data Model or Physical Database Design
Conceptual data model gives us the high-level overview of the application by providing us the different entities in our data and the relation between them.
Logical data model gives us the basic details of the data without caring too much about exact types of data to be used.
Physical data model gives us the exact implementation of the type of data to be used.
The Conceptual data model is the simplest of all and the complexity increases through the Physical data model. In some cases, the Conceptual data model and Logical data model is combined and treated as a single data model. So in those instances, you may find only Logical data model and Physical data model.
So generally, a database design has three parts. Designing these three parts is what is called as Data Modeling and those individual parts are called as Data Models. These three data models are Conceptual Data Model or Conceptual Database Design, Logical Data Model or Logical Database Design, Physical Data Model or Physical Database Design. In our next articles, we will see what these individual data models are in great length.