Relational database developers have long used the term “Entity” when designing database schemas. Meanwhile, on the software architecture side, the term “Entity” is a key component of domain-driven design. So what is the difference? Or is there a difference? Do they refer to the same thing?

Many software systems use a batch-driven process to operate. They accumulate data in a database and periodically a job will process the data to produce some result. In the past, this was sufficient. However, modern systems need to respond faster. They may not be able to wait for a batch to start. Many systems have turned to an Event-Driven approach because it is capable of reacting to events as they happen. However, despite the power of these systems, they do introduce new challenges.

When building a table in a SQL database, one of the most important decisions is what to use for a primary key. This can have a big impact on the efficiency of your queries. It also becomes critically important when you start creating relationships between tables.