concept application tier in category nosql

This is an excerpt from Manning's book Making Sense of NoSQL. Login to get full access to this book.

Using application tiers in your architecture allows you to create flexible and reusable applications. By segregating an application into tiers, you have the option of modifying or adding a specific layer instead of reworking an entire application when modifications are required. As you’ll see in the following example, which compares RDBMSs and NoSQL systems, functions in NoSQL applications are distributed differently.

When application designers begin to think about software systems that store persistent data, they have many options. One choice is to determine whether they need to use application tiers to divide the overall functionality of their application. Identifying each layer breaks the application into separate architectural components, which allows the software designer to determine the responsibility of each component. This separation of concerns allows designers to make the complicated seem simple when explaining the system to others.