NHibernate Hierarchichal data fetching with single query

I have a table in DB where columns are like below.

Id   Name     Publisher          ParentId
------------------------------------------    
100  Sample1  ExamplePublisher   NULL
200  Sample2  ExamplePubl3       100

NHibernate mapping is like below.

   <cl开发者_Python百科ass name="PaperMaster">
        <composite-id>
            <key-property name="Id"></key-property>
            <key-property name="AreaId"></key-property>
        </composite-id>       
        <property name="Name"></property>
        <property name="Parent"></property>
        <property name="Publisher"></property>
        <property name="YearStarted"></property>
        <bag name="ChildCollection" table="PaperMaster" lazy="false" 
                  inverse="true">
            <key>
                <column name="Parent"></column>
                <column name="AreaId"></column>
            </key>
           <key column="Parent"></key>
            <one-to-many class="PaperMaster"></one-to-many>
        </bag>        
        <many-to-one name="ParentObject" column="Parent">
            <column name="Parent"></column>
            <column name="AreaId"></column>
        </many-to-one>        

    </class>

When I query NHIbernate like below I am successfully getting the object with child collections filled in properly.

   IList<PaperMaster> allList = se.CreateQuery("select e from PaperMaster e join fetch
      e.ChildCollection where e.Id=100")
                .SetResultTransformer(new DistinctRootEntityResultTransformer())
                .List<PaperMaster>();

The problem I am facing is for each child a query runs to fill the object which seems to be very costly. Is there a way to simplify this? For example in a single query I should be able to get the full relation.

One way to reduce the amount of queries is to add batch-size="25" on your bag mapping.

e.g.

 <bag name="ChildCollection" table="PaperMaster" lazy="false"
     batch-size="25" inverse="true">

This will reduce the amount of queries dramatically.