Introduction to Data Modeling

As data engineers, one of our main objectives is to drive the business forward. However, sometimes stakeholders know what they want, but they struggle to articulate it and transfer their domain knowledge into a database design. This is where data modeling comes in. It helps us translate business requirements into a visual representation of data and the relationships among data points.

Data can be modeled at various levels of abstraction. The process starts by collecting requirements from business users. These requirements are then translated into a database design consisting of entities and attributes.

A good data model captures how work naturally flows within the organization. A better data model can accommodate business changes without disrupting the foundational database design. The process of converting business ideas into database design involves three steps, each representing different levels of abstraction as models are developed. In this lesson, we will learn about the data modeling process with a real-life use case.

Use case

The best way to learn data modeling is to work through examples. In this lesson, we will build a data model for a large grocery chain. The business has 100 stores spread out worldwide. Each store has roughly 1000 individual products. Customers may or may not use their memberships to purchase products. The business aims to design a database system to keep track of sales and use the data to maximize profits.

Conceptual data models

The data modeling process starts with high-level abstraction, namely a conceptual model. A conceptual data model provides a big picture of the system's contents and business rules, without going into the details of the database. It focuses on defining entities and the relationships between them. A typical way to visualize a conceptual model is through Entity-Relationship (ER) diagrams.

Define business process

To begin the design process, the first step is to determine which business process to model. A business process refers to a low-level activity carried out by the organization, such as taking orders, receiving payments, or processing customer requests. In this case, the business process is sales transactions.

Determine key entities