Implementing Domain-Driven Design

Tactical Modeling

We model tactically inside a Bounded Context using DDD’s building block patterns. One of the most important patterns of tactical design is Aggregate (10), as illustrated in Figure G.4.

Figure G.4. Two Aggregate types with their own transactional consistency boundaries

An Aggregate is composed of either a single Entity (5) or a cluster of Entities and Value Objects (6) that must remain transactionally consistent throughout the Aggregate’s lifetime. Understanding how to effectively model Aggregates is quite important and one of the least well understood techniques among DDD’s building blocks. If they are so important, you may ...