[AccessD] Slo-o-o-w ODBC connection to Oracle

x-posted to Access-L and Access-D

I'm hoping someone out there has some experience of this. This is my first time working a non-Access back end.

Using Access 2010 connected to an Oracle 10g back end and using a System DSN.

It is HORRIBLY slow!!  Here's the scenario.

I have a table of people (~20,000 rows) and a table or related assets (~24,000 rows), and I'm displaying the data in a form/continuous sub form setup. The Main form and Sub form a linked via the Primary key of the people table and the corresponding foreign key in the assets table.

The main form is bound to the people table via a simple select query. The record source of the form is set when a person is selected from an unbound combobox...
            Me.RecordSource = "select * from MyQuery Where ID=" & ComboBox.
This same combobox selection also sets the record source for the continuous sub form
            Me.View_Data_sub_frm.Form.RecordSource = "Select * from AnotherQuery Where FKID=" & ComboBox

When the front end is hooked up to an Access back-end (and MDB file) it takes about 0.1 seconds to set the form record source, and another 5.5 seconds to set the sub-form record source and display the data.

When connected to the Oracle back end the record source of the main form is a Pass Though query as it is calling a decrypt function in the Oracle back end, the record source of the sub-form is the same query as used with the Access back end. Setting the record source for the main form now takes about 70 seconds and it takes a further 40 seconds to set the sub form record source.  In the first step - setting the main form record source, if I just use the original non-pass through query it takes about 40 seconds to select the data, and another 40 to get the related data.

Any thoughts on improving these awful response times?

Lambert