Here is a couple suggestions.

Maybe try using a stored proceudre.
Try turning on ODBC logging. See whats happening at that level.
Check the oracle odbc driver documentation, it might be a limitation that it has. http://otn.oracle.com/tech/windows/odbc/index.html
Check the oracle odbc formus here: http://forums.oracle.com/forums/forum.jsp?forum=145




>One of my friend have a problem...
>
>Here's the problem...
>
>I'm attempting to link together a SQL Server 2000 with Oracle 8.
>
>I have a linked server (Oracle) defined in SQL Server.
>
>On Oracle side, I have a table called EMPLOYE that is accessible to SQL Server through the link. In SQL Server, I have a view called VW_EMP that contain : "select * from LNK_ORACLE..SQL.EMPLOYE"
>
>In SQL Query Analyser, if I execute:
>"select * from VW_EMP where employe = 12345"
>The explain plan display 2 stages (SELECT, REMOTE QUERY) and the command "select * from LNK_ORACLE..SQL.EMPLOYE where employe = 12345" is sent to Oracle. The answer is instantaneous.
>
>BUT, if my command is
>"select * from VW_EMP where employe = 54321"
>The explain plan display 3 stages (SELECT, FILTER, REMOTE QUERY) and the command "select * from LNK_ORACLE..SQL.EMPLOYE" is sent to Oracle (without the WHERE clause). The answer is very slow because the filter is done on SQL Server side so the full content of the table is sent to SQL Server.
>
>After many hours of searching, I realize that when my employe number is higher that 32768, SQL Server do not sent the WHERE clause !!!
>
>How can I force SQL Server to always send the WHERE clause ? or how can I get rid of this filter stage (which is obviously slowing it all down)?
>
>Help is really appreciated...