title: What are read-models within Aggregates in DDD and where to use them?
body: <p>I know in DDD that deleting an Aggregate root would mean removing everything within the Aggregate boundary at once.</p>
  
  <p>But I have noticed that read-models(read-only properties) are used within aggregates as Lev Gorodinski stated in this blog: <a href="http://gorodinski.com/blog/2012/04/25/read-models-as-a-tactical-pattern-in-domain-driven-design-ddd/" rel="nofollow noreferrer">http://gorodinski.com/blog/2012/04/25/read-models-as-a-tactical-pattern-in-domain-driven-design-ddd/</a></p>
  
  <p>But as those models are part of the aggregate.So,how we treat them in case of deleting or updating our aggregate?</p>
  
  <p>Also,can we use them to ensure the invariants/consistency of Aggregates?</p>
  
  <p>I would appreciate an example about them and how we use them within aggregates without violating DDD principles.    </p>