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I am trying to decompose my relation:

R = (A, B, C, D, E) with Functional Dependencies F = {D -> BC, E -> B, A -> B, B -> D}

The problem is that D appears in two dependencies and in different capacities. So after I do my first stage of the decomposition, I have an FD that no longer makes sense.

To illustrate, starting with the FD B -> D, I split R into:

R1 = (B, D) R2 = (A, B, C, E)

and Functional Dependencies become: F = {D -> BC, E -> B, A -> B}

The problem is that D -> BC now makes no sense as these attributes don't even appear in the same table anymore.

How can I get around this issue, and how do I find the correct BCNF for this relation?

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