The EnableObjectTracking property is only used when selecting data from a LINQ To SQL data context object.
When you are interacting with read-only data, setting the EnableObjectTracking property to false improves performance because the data is not cached to determine if it has changed. However, it also disables deferred query execution. This property must be set to true if you want to use deferred query execution.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)