Typically, data access consumes more time than any other part of your application. How you design your data access can have a dramatic impact on your application’s overall performance. For example, while the Entity Framework is the most convenient way to access a database, performing a query with the Entity Framework takes far longer than using ADO.NET. Similarly, while creating granular web services is a best practice, you can often improve performance by creating Data Transfer Objects (DTOs) that combine the results of multiple granular web services queries.

This objective covers several topics related to the optimization of data services, including the performance impact of Object Relational Mapping (ORM), how to optimize round-trips to web services, and how to use lazy and eager loading.