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Design Algorithm Essentials 1.Combine functional edges with the same tail object set(s) into a scheme. (The tail object set(s) and any others in a 1-1.

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Presentation on theme: "Design Algorithm Essentials 1.Combine functional edges with the same tail object set(s) into a scheme. (The tail object set(s) and any others in a 1-1."— Presentation transcript:

1 Design Algorithm Essentials 1.Combine functional edges with the same tail object set(s) into a scheme. (The tail object set(s) and any others in a 1-1 correspondence are keys.) 2.Each nonfunctional edge is a scheme. (All object sets constitute the key.) 3. Each stand-alone object set is a scheme. (The lone object set is a key.) A B C A B C A B C AA ABA B A B C A B C A B C A B C D D A B C D

2 B&B Example – Canonical

3 B&B Example – Generated Database Scheme Room(RoomNr, RoomName, NrBeds, Cost) Guest(GuestNr, GuestName, StreetNr, City) Reservation(GuestNr, RoomNr, ArrivalDate, NrDays) Room[RoomNr]  Reservation[RoomNr] Guest[GuestNr] = Reservation[GuestNr]

4 B&B Example – ORM Diagram

5 B&B Example – ORM Hypergraph

6 B&B Example – Congruent

7 B&B Example – Canonical

8 B&B Example – Generated Database Scheme Room(RoomNr, RoomName, NrBeds, Cost) Guest(GuestNr, GuestName, StreetNr, City) Reservation(GuestNr, RoomNr, ArrivalDate, NrDays) Room[RoomNr]  Reservation[RoomNr] Guest[GuestNr] = Reservation[GuestNr]


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