How is Span used? What is Span? (aka. How does the EF support eager-loading?
The span feature makes it possible to pre-fetch related entities. Span can be defined as a builder method, “Include”, which makes it simpler to specify span rules in LINQ to Entities queries. Include can be called on the ObjectQuery used in the from clause of the LINQ query. Span makes it possible to specify that a query not only return an entity but return some set of related entities in a single round trip and automatically hook-up the graph. So, for instance, you could say that your customer query should also return the orders for each customer in a single round trip. We also have an automatic query re-write feature for the object layer that enables a feature we call Relationship Span where queries that retrieve entities will under-the-covers also return relationship information if the relationship is an EntityReference (rather than a collection).
