Salesforce.com SOQL supports selecting parent record value through reference key name.
We need to query parent record info from child table query. For example, if I have column parentid in Contact object which is reference key to account object, I can do in SOQL in salesforce.com something like this.
Select c.Id, c.Name, c.AccountId, c.Account.Name
from Contact c
But if i want to do the same in EDS, I have to use Relationship Queries (join of two tables Account and Contact) which is huge impact on performance