What do I miss when passing an URL a parameter to a query?

Question

Hello,
Here I am again with my problem. I am trying to understand what happens behind the whole thing to achieve the best performance.
I have a single page which accepts a parameter. Since I must have one page I cannot use the "ExecuteWithParameters" method for passing parameters.
This page has one VO with a bind variable. The query takes a lot of time to compute.
For now to use a paramter from the URL I do the following:
1. In the page properties I associate a parameter with a variable in the sessionScope (I need it to be in the session):
<from-value>#{param.my_param}</from-value> <to-value>#{sessionScope.my_param}</to-value>
First doubt: is anything in the sessionScope defined as above available immediatly without registering any bean?
2. Next step is to go in the pageDefs and define a methodCall with an InvokeAction:
<executables>
<variableIterator id="variables"/>
<page path="oracle.ui.pattern.dynamicShell.model.dynamicTabShellDefinition"
id="pageTemplateBinding" Refresh="ifNeeded"/>
*<invokeAction Binds="setmy_param" id="setParams"/>*
</executables>
<bindings>
<methodAction id="setmy_param" RequiresUpdateModel="true"
Action="invokeMethod" MethodName="setmy_param"
IsViewObjectMethod="true" DataControl="AppModuleDataControl"
InstanceName="AppModuleDataControl.TreeViewObj1">
*<NamedData NDName="value" NDValue="#{sessionScope.my_param}"*
NDType="java.lang.String"/>
</methodAction>
The method setmy_param is a VO method exported to the client.
NOW:
When the page starts and the UI component built on the VO is rendered, it looks like the VO keeps ignoring the bind variable set with the method.. I mean, it seems the query is executed BEFORE the setmy_param() is executed on the VO (no matter the order of the bindings in the pageDef).
For this reason the only workaround seems to be to RE-EXECUTE the query in the method. But this takes a lot of time since the query is time consuming. Is there a way to associate the parameter to the bind variable in VO BEFORE the first execution of the query at the start of the page, basically when the component based on VO is rendered?
Thanks.

Answer 1

I missed this
Refresh="prepareModel"
in the InvokeAction section