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1. For a Movies database with a Person entity and a Movie entity which have a relationship
Acts_In, suppose we wanted to add a count of the number of movies for each person -- that is,
how many movies has an actor played a role in. How should we model this?
a) Add the count as a regular attribute of the Person entity
b) Add the count as a regular attribute of the Acts_In relationship
c) Add the count as a derived attribute of the Person entity
d) Add the count as a derived attribute of the Acts_In relationship
2. Suppose that for an entity E, there are two candidate keys, A and B. A is a VARCHAR of up
to 20 characters while B is a REAL. The primary key should be:
a) A
b) the pair of A and B
c) B
d) either A or B, there is no meaningful difference without further information

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  • 1. 1. For a Movies database with a Person entity and a Movie entity which have a relationship Acts_In, suppose we wanted to add a count of the number of movies for each person -- that is, how many movies has an actor played a role in. How should we model this? a) Add the count as a regular attribute of the Person entity b) Add the count as a regular attribute of the Acts_In relationship c) Add the count as a derived attribute of the Person entity d) Add the count as a derived attribute of the Acts_In relationship 2. Suppose that for an entity E, there are two candidate keys, A and B. A is a VARCHAR of up to 20 characters while B is a REAL. The primary key should be: a) A b) the pair of A and B c) B d) either A or B, there is no meaningful difference without further information