Limiting fields in Select statement generated by Linq to Castle ActiveRecord

I'm using ActiveRecord and LinqToActiveRecord to query my database. The problem is, that the generated SQL statement from my LINQ expressi开发者_Go百科on always tries to select all possible fields, including joined tables, when this is not needed. For example, I have these database tables:

Table: MasterTable
Id (int)
ChildId (int) <- references a record in the Child table

Table: ChildTable
Id (int)
ChildName (varchar)

Now I want to query all Master records of which the referenced Child record contains ChildName "Tijn":

var myList = (from master in MasterTable.Queryable
              where master.Child.ChildName == "Tijn"
              select master).ToList(); 

The generated SQL statement tries to select not only all Master fields, but the joined Child fields too! When I try the same using HQL:

select master from MasterTable master where master.Child.ChildName = 'Tijn'

the generated SQL statement only includes the master fields, like I wanted to.

So, to be short: How can I 'limit' / 'constrain' the tables of which fields are selected in LINQtoActiveRecord / LINQtoNHibernate? Some kind of 'projection' or extended 'Select' method?