When does a compiled query that returns an IQueryable execute?

Question

Okay I need a sanity check here...

I've compiled a query that returns an IQueryable when executed.

On what line(s) should the query actually execute against the database in the following example?

101 IQueryable<T> results = MyCompiledQuery(MyDataContext);
102 List<T> final = (from t in result
103                  where t.ID > 5
104                  select t).ToList<T>();

Here is how I define the compiled query

 public static Func<MyDataContext, IQueryable<Widget>> MyCompiledQuery=
        CompiledQuery.Compile<MyDataContext, IQueryable<Widget>>(
                      (MyDataContext db) =>
                      from w in db.Widgets
                      where ((w.Type == WidgetType.Atype ||  //Widget.Atype is a Linq to Sql object, that I've defined statically
                              w.Type == WidgetType.Btype ||  //See above comment
                              w.Type == WidgetType.Ctype ) && //See above comment
                              w.Location == WidgetLocation.Domestic)  //Samething applies here
                        select euc);

Answer 1

On the line 104, when doing ToList conversion.

Answer 2

It executes at line 104 (when you call ToList()).

A compiled query is a query that is translated only once to TSQL at compile time, instead of everytime prior to execution.

Answer 3

This is called Deferred Execution.
You can read a good post on it here.

Answer 4

On line 102. The lines 102-104 is a single statement, and the query is executed when the ToList method reads from the IEnumerable that the LINQ statement creates.