- Aggregates
Aggregate is a specific type of Entity
- An Aggregate is a collection of domain objects bound to a root entity.
- The root entity is called the Aggregate root.
- Objects in an aggregate can be treated as a single unit.
- Access to objects in the aggregate must go through the aggregate root.
- Transaction should not span multiple Aggregate Roots.
- Aggregates are good candidates for distribution in a Reactive System.
- Determining the Aggregate Roots
- Choosing an aggregate root is not always straightforward.
- the aggregate root can be different from one context to another.
- some contexts may require multiple aggregate roots.
- some questions to consider:
- is the entity involved in most operations in that bounded context?
- if you delete the entity, does it require you to delete other entities?
- will a single transaction span multiple entities?
