Accessing a database for persisted data retrieval is usually a time-consuming operation. Within the .NET framework, ADO.NET is the sub-framework responsible for database access. In 2008, Microsoft introduced Entity Framework (EF) as a multiplatform object relational-mapping (O/RM) database access subsystem within ADO.NET itself.
Although classical ADO.NET (low level) database access techniques have been superseded by EF's features, some specific usage is still a prerogative of such legacy programming classes.
In this chapter, we will take a tour of EF's querying capabilities, trying all available techniques to emphasize the performance results of each one. We will cover the following topics in this chapter: