The tier aspect model addresses Aspect Oriented Programming (AOP) in the context of database applications. It is a new technique of separation of concerns through tiers implemented as virtual object-oriented updatable views. The code of an aspect related to particular objects is encapsulated within a separate view that overrides all generic operations performed on the objects. Aspect tiers form a chain of views. Such additional codes can do any extra action e.g. security, licensing, integrity constraints, monitoring and others. The idea is based on the Stack-Based Approach to object-oriented query languages and the novel idea of virtual updatable views.