We are given table APPEARS-IN(actor-name,age,sex,movie-title,year,director,studi

ID: 3828103 • Letter: W

Question

We are given table APPEARS-IN(actor-name,age,sex,movie-title,year,director,studio,budget,salary) and the following information:

• each actor is identied by his/her name, and (obviously) has one age and one sex.

• each movie is identied by a title and year, and has a single director and budget, and is produced by a single studio.

• each actor agrees to appear in a movie for a certain salary.

Answer the following questions:

i. Write the functional dependencies represented by the above information.

ii. Find all the keys of APPEARS-IN.

iii. Find a decomposition of APPEARS-IN in 3NF.

iv. Prove that your decomposition is lossless.

i) functional dependencies

actor-name -> age

actor-name -> sex

movie-title -> year

movie-title -> director

movie-title -> studio

movie-title -> budget

actor-name -> salary

ii) keys

actor-name,movie-title

iii) 3NF

ACTOR(actor-name,age,sex,salary,movie-title)

MOVIE(movie-title,year,director,studio,budget)

underlined are primary keys and italicised is

iv) decompostion is lossless

if we join the two tables ACTOR and MOVIE , we get all the values in the APPEARS-IN table

Select A.* ,M.* from ACTOR A inner join MOVIE M on A.movie-title = M.movie-title;

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