Server side code uses custom code to mark leafs|branches - data generated a lot faster ( about 5x ) than for default sample.
01p_basic_connector.cfm:
<cfinclude template="../config.cfm">
<cffunction name="child_setter">
    <cfargument name="data" type="any" required="yes">
    
    <cfif ARGUMENTS.data.get_value("taskId") mod 100 gt 1>
        <cfset data.set_kids(0)>
    <cfelse>
        <cfset data.set_kids(1)>
    </cfif>     
</cffunction>
<cfset tree = createObject("component",request.dhtmlxConnectors["tree"]).init(request.dhtmlxConnectors["datasource"],request.dhtmlxConnectors["db_type"])>
<cfset tree.event.attach("beforeRender",child_setter)>
<cfset tree.render_table("tasks","taskId","taskName","","parentId")>