Left-join read-ahead

[ebu]

Hi.
Could somebody provide a sample app with working Left-join read-ahead mechanism for jboss 4.0? I.e. it should generate LEFT OUTER JOIN clauses in resulting SQL query as it is descirbed in http://www.jboss.org/wiki/Wiki.jsp?page=LeftJoinReadAhead

Btw, as far as i can see in the sources org.jboss.ejb.plugins.cmp.jdbc.SQLUtil.LEFT_OUTER_JOIN is used in the JDBCLoadEntityCommand.getDeepSQL only, which is commented out completely ... Am i missing something?

Thanx.

wbr, evgen.

[jobor]

I'm using 3.2.6. In the example query I always want to read the info of 2 parent EJB's when selecting specific entities. So the query element looks like

<query>
 <query-method>
 <method-name>findByNumber</method-name>
 <method-params>
 <method-param>java.lang.String</method-param>
 </method-params>
 </query-method>
 <read-ahead>
 <strategy>on-find</strategy>
 <page-size>64</page-size>
 <eager-load-group>all</eager-load-group>
 <left-join cmr-field = "type" eager-load-group = "all"></left-join>
 <left-join cmr-field = "archive" eager-load-group = "all"></left-join>
 </read-ahead>
</query>

The <page-size>64</page-size is only useful for loading fields that are not in an eager load group. So in my example the page size is not needed because I have small EJB's with a small amount of entities returned. If you have a large EJB with fields that are not needed then you better do something with on-load, lazy the page size and lazy loading.

Johan.