Access 97 ODBC to Oracle Question

Hi, during the course of developing an application using MS Access 97 as front end to retrieve data from a few fairly large Oracle tables (one has over 1 million rows). We ran into a performance problem and makes me wonder if Access actually takes advantage of Oracle indexes. Since Access does not let us change the table structure, we could not add the indexes to these linked tables. In all cases, the performance of these queries are slower than the equivalent pass-through queries. If we actually download the data and create the same Access tables and indexes just like Oracle, the performance is still much slower than Oracle which runs on a large Sun Enterprise server. Another thing we noticed is that the performance is some times even data dependent, i.e. in "Select ....from .,.,.,. where ... column = value;", using value 1 the result returned almost right away and using value 2 took half a minute or longer. Does Access return the result when it has found enough rows to fill in the first page and worry about the rest later (when you scroll down). If so, Access must scan down the table and it found rows belong to value 1 (which is more popular) much sooner than it can find rows for value 2. Any help to clarify this mystery will be greatly appreciated. Feel free to e-mail me or follow-up to this posting. Have a great day!

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Regards,
Ben Lin
ben.lin_at_unocal.com