Data Modeling: Embracing the Dynamics of the 'Person' Entity (Part 3 of 8)

February 4, 2024 (1d ago)


In our previous chapters, we traversed the structured lands of 'Organization' entities, unveiling the pillars upon which businesses rest. Today, we turn our gaze to the 'Person' entity, venturing beyond the static confines to a model where change is not only acknowledged but intricately mapped.

Person: A Basic Model

When we first attempt to encapsulate a 'Person' within our data realms, we might conceive a straightforward structure akin to a still life painting—it captures the essentials: a name, a gender, a birthdate. This initial model is a solid foundation, a starting point upon which many systems are built, offering a simple, unchanging view of personal data.

Person Basic Entity Diagram

The diagram we behold here serves as our initial blueprint, a reference point from which to understand the basic 'Person' entity.

When Simplicity Suffices... And When It Falls Short

This simplicity serves well in scenarios where the data is as static as the model itself—where individuals' roles and attributes remain constant, and the passage of time is but a distant thought. However, this model falters when faced with the fluidity of human existence. The static nature of this model means it cannot gracefully accommodate the evolution of personal circumstances—such as name changes, varied physical states, or shifting marital statuses—leaving us with a disjointed and incomplete record.

Introducing the Alternate Model

Acknowledging these limitations beckons the need for a more advanced approach. Thus, we introduce the alternate model, a dynamic and historical construct that respects the transience and permanence of personal attributes.

Person Alternate Entity Diagram

As shown in the alternate model above, each aspect of a person's journey is given its due space to evolve, allowing us to track the changes and maintain a cohesive narrative of each individual.

Comparative Analysis

When we look at the basic and alternate models side by side, we see two different ways to think about data modeling. The basic model is simple and doesn't change, while the alternate model can handle changes over time.

The basic model works well for simple apps. For example, if you have an app for a one-time event sign-up or a basic online store where people buy things without creating an account, the basic model is enough. In these cases, you don't need to keep track of changes to people's information because each interaction is quick and standalone.

On the other hand, the alternate model is great for apps that need to keep track of changes in people's lives. Think of health apps, customer service software, or any system where you need to remember past information about someone. In these apps, people's details like names and health can change often, and relationships with companies can start and stop. The alternate model is built to keep a full history of these changes. It helps you see the whole picture and understand each person better.

By comparing the two, we can see that the simple model is best for one-time or quick interactions, while the more complex model is needed for situations where it's important to know the history and changes in someone's information. The smart choice of which model to use depends on what your app needs to do.


As we model the 'Person' entity, we learn that data, akin to life, requires both the anchor of stability and the sails to catch the winds of change. With anticipation, we shall explore the 'Party' entity next, where the paths of 'Person' and 'Organization' entities converge and continue our journey through the complex landscapes of data modeling.