>From what I read in the manual the "on_find" will load me all the matched 
>records, 
which may be a lot or even to much, 
therefore there is the "on_load" which only loads the "page_size" specified 
number of records. 
But in all the examples the "on_find" also has the "<page_size>" tag so now I 
am lost. 
Is this tag superfluous in case of "on_find" or are there other differences. 
Is there a different meaning for "on_find" and "on_load" when specified by a 
ejbfindBy or ejbSelect, and in a relation?
 
Where to specify the read ahead tags on 1..n relations in order to:
Load the fields of the related entity bean when accessing the getter from the 1 
side.
Loading all the entities (and eventually some of there field data) when 
accessing the getter from the n side.
What do I have to specify where?
Here is an example which may (hopefully) clarify my question
I used XDoclet tags and the resulting xml is at the end.
 
 
In an Entity Bean (called Leaf) there is a method to retrieve the links from 
this Leaf
/**
*
* @ejb.interface-method
*   view-type = "local"
*
* @ejb.relation
*   name = "fromLeaf-linkFroms"
*   role-name = "LeafLinkFromsRelationshipRole"
* 
* @jboss.relation-read-ahead 
*   strategy = "on-find"
*   eager-load-group = "allFields"
*/
public abstract java.util.Collection getLinkFroms();
 
 
The Link class the related to Leaf contains the corresponding method
 
/**
*
* @ejb.interface-method
*   view-type = "local"
*
* @ejb.relation
*   name = "fromLeaf-linkFroms"
*   role-name = "LinkFromLeafRelationshipRole"
*
* @jboss.relation
*   fk-column = "FROMLEAF_PKLEAFID"
*   related-pk-field = "pkLeafId"
* 
* @jboss.load-group
*   name = "allFields"
* 
* @jboss.relation-read-ahead 
*   strategy = "on-find"
*   page-size = "1000"
*   eager-load-group = "allFields"
*/
public abstract com.ascom.opentas.as.element.internal.entitybeans.Leaf 
getFromLeaf();
 
 
In my jbosscmp-jdbc.xml file the corresponding entry looks like
 
 
<ejb-relation>
         <ejb-relation-name>fromLeaf-linkFroms</ejb-relation-name>

         <ejb-relationship-role>
           
<ejb-relationship-role-name>LinkFromLeafRelationshipRole</ejb-relationship-role-name>
                       <key-fields/>

           <read-ahead>
             on-find
             <page-size>1000</page-size>
             <eager-load-group>allFields</eager-load-group>
           </read-ahead>
         </ejb-relationship-role>
          <ejb-relationship-role>
           
<ejb-relationship-role-name>LeafLinkFromsRelationshipRole</ejb-relationship-role-name>
           <key-fields>
              <key-field>
                <field-name>pkLeafId</field-name>
                <column-name>FROMLEAF_PKLEAFID</column-name>
              </key-field>
           </key-fields>

           <read-ahead>
             on-find
             <eager-load-group>allFields</eager-load-group>
           </read-ahead>
         </ejb-relationship-role>
</ejb-relation>
 
We currently are using jboss-3.2.6RC2 (with JRE 1.4.2_07) together with 
Oracle9i as DB

Many many thanks for any help, information or suggestion to a person in 
distress.
 
Percy Christian
 



View the original post : 
http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3875381#3875381

Reply to the post : 
http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=3875381


-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
JBoss-user mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/jboss-user

Reply via email to