exercise6 SSD7

Answer for exercise7 SSD7
1)
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PK (TrackingNum)
Because no matter how many employees are handling one order tracking number will always 
define a unique row.
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2)
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fd1: TrackingNum --> {EmpID, EmpName, OrderNo, ShipToAddr, ShippedDate}
fd2: EmpID -->  {EmpName}
fd3: OrderNo --> {ShipToAddr}
fd4: {EmpID, OrderNo}  --> {ShippedDate}
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3)
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EmpID EmpName OrderNo ShipToAddr ShippedDate TrackingNum 
1234 Joe  223    xyz   12/21/99    12435678 
1234 Joe  223    xyz   12/21/99    12435677 
6666 Max  666    xyz   12/21/99    12435676 
5555 Rom  223    xyz   12/21/99    12435675

a) Modification anomaly: If we try to change name of employee having EmpID='1234' then row number two might not get updated.


b) Insertion anomaly: We cannot insert a new employee unless he makes a shipment and gets a tracking number.