Oracle ODBC Driver adds bind variable when browsing whole table in Access

Question

Hi, we are looking for some reasons why we may see this behavior in the Oracle ODBC driver (10gR2 and 11g) when using Microsoft Access (2003 or 2007)...
1) Link a table from the Oracle database.
2) Double-click the newly linked table to "browse" it.
Oracle sends the following statement to the server:
{color:#0000ff}select * from linked_table where primary_key = :b1{color}
It then proceeds to read the entire table.
If I tell Microsoft Access that there is no primary key, the query gets sent as:
{color:#0000ff}select * from linked_table{color}
And the query comes back as soon as the first 100 or so rows are fetched which is quite quickly.
ADDITIONAL NOTES:
1) If the table has a primary key or unique constraint, Microsoft Access automatically assigns that as the primary key.
2) We can stop the behavior in #1 if we wrap a view around it which prevents Access from discovering that information and then it prompts for a primary key definition.
3) If we use the Microsoft ODBC driver, the bind variable is not added no matter what the primary key defintiion is.
We're stumped and are looking for solutions and/or workarounds without having to wrap all of our tables in views to hide the fact that there is a primary key.
Thanks,
Steve

Answer 1

Thanks for the response, Greg.
The specific question I am seeking an answer for (sorry it was not clear on my first message) is this:
Why does the Oracle driver add the bind variable to the query only when the primary key is defined?
The Microsoft ODBC driver does not add the bind variable with or without a primary key defined.
You asked how I traced this statement and what I am doing is launching the query in Access and then using TOAD to view the V$SESSION and V$SQL_TEXT_WITH_NEWLINES views. All I do is change the driver. This is just for a simple browse table (double-click on the table) which should send
select * from table
However, whenever I use the Oracle ODBC driver (with a primary key defined) it sends
select * from table where primary_key = :1
If I remove the primary key on the table definition, the Oracle driver sends
select * from table
What is it about the primary key that could cause that behavior?
I don't think it is the MDAC/Jet level because this is the conversion to the native SQL statement not the Jet version. I know the Oracle driver has to do that part because you have those workaround options like don't add the RULE hint, etc. That's not part of the Jet engine.
Hope that helps. I'm just baffled over this one and wish I knew where to go next.