Correct Decompositions
• A decomposition is lossless if we can recover:
•                 R(A,B,C)
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•
•             R1(A,B)      R2(A,C)
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•
•                   R’(A,B,C)   should be the same as
                                    R(A,B,C)
R’ is in general larger than R.  Must ensure R’ = R
Decompose
Recover