Inference control with oracle

Question

Hi,
I need for my master thesis a possibility to realize inference control with oracle.
For example exist an instance R like
R   |   A    B    C
    |  a1   b1   c1
    |  a2   b1   c2
and a secrecy such *(exists X) R(a1, b1, X)*. With VPD under column hiding can defined this secrecy so that the data combination *(A:a1, B:b1)* be hidden from the instance:
R   |  A    B    C
    |            c1
    |  a2  b1   c2
The Problem is that a safe query like *(exists X)(exists Y) R(a1, X, Y)* was not answered, when the user makes a query
select A from R where A=a1;
Cause this query is a safe query with respect to the secrecy, the answer must not be hidden.
Safe means
*(exists X)(exists Y) R(a1, X, Y) NOT MODELS OF (exists X) R(a1, b1, X)*.
How can I avoid this.
I tried to avoid that whit using "query rewriting" and "materialized view", but that was not successfull, because oracle doesn't rewrite the simple (without Aggregates and Joins) queries.
It will be greate when someone has an idea!
Thanks

Answer 1

As curious as I always am, I was able to discover my XE database from the GC 10.1.0.4 last month. I did this because I asked myself the same question. When there is time, I normally will try everything that says "Not supported" or "Not compartible" to prove it right or wrong. So give it a go, but don't post errors from it here :-). I have not tried it for GC 10.2.0.2, but it worked on 10.1.0.4 (hopefully 10.1.0.3).
Remember, XE has all the features of EE, but a cutdown version. It has an Oracle Service and a Listener on a port, so the agent will pick them up. I have tried all possible things and tools (Forms, Reports, Designer Repository, Jdeveloper, SQL Developer, ODBC, JDBC etc) on XE to break it, but it works like EE. The only difference is when you hit the max allowed 4GB (excluding 1GB system) and I proved the limit right by kicking of a data load into a table using a cursor until it hit the maximum 4GB limit error.