HW - 05-07-2010

HW - 05-07-2010 - Waqas Javed ID: 982800 Exercise 13.10...

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ID: 982800 Exercise 13.10 Full Functional dependency indicates that id A and B are attributes of a relation, B is fully functionally dependent on A if B is functionally dependent on A, but not on any proper subset of A. Functional dependency A B is a full functional dependency if removal of any attributes from A results in the dependency no longer existing. It has a very strong relation with 2NF, because in 2NF every non-primary key attributes should be a full functional dependent on primary key. Example: guestN o guestNam e guestAddres s roomN o type price hotelN o hotelNam e city From To 1 John 1000 N Fairfield, IA 1 Double 46.00 1 Grosveno r Hotel London 05/06/20 10 05/06/20 10 Hotel_No HotelName, City (Partial Dependency) GuestNo guestName, guestAddress (Partial Dependency) GuestNo, HotelNo, From To, roomNo, type, price (Primary key) roomNo type, price (transitive dependency) So, we can separate full dependencies. guestN o guestName guestAddress 1 John 1000 N Fairfield, IA guestN o hotelN o From To roomNo type price 1 1 05/06/20 10 05/06/20 10 1 Double 46.00 Exercise 13.11 Transitive dependencies indicates that where A, B and C are attributes of a relation such that id A B and B C, then C is transitive dependency on A via B (provided that A id not functionally dependent on B or C). hotel
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HW - 05-07-2010 - Waqas Javed ID: 982800 Exercise 13.10...

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