51
P.A. Bernstein, S. Melnik: Meta Data Management, ICDE'04 Boston
mR
OrderID
Product
Rebate/Discount
ShipDate
Design
pattern
OrderID
Product
Brand
Discount
ShipDate
OrderID
Product
Rebate
OrderID
Product
Brand
m
mA
mB
m_mA
m_mB
m_mR
Need model m to identify additions / deletions in mA and mB.
Cannot simply merge mA and mB (deletions are lost).