video centers of europe, ltd., is a chain of movie DVD rental stores. it must ma

Question

video centers of europe, ltd., is a chain of movie DVD rental stores. it must maintain data on the dvds if has for rent, the movies recorded on the DVDs, its customers, and the actual rental. each dvd for rent has a unique serial number. movie titles and customer numbers are also unique identifiers. assume that each movie has exactly one "star." note the difference in the year that the movie was originally filmed and the date that a dvd an actual disk was manufactured. some of the attributes and functional dependencies in this environment are as follows:

attributes:

dvd numbers, manufacture date, movie title, star, year filmed, length (min), customer numbers, customer name, customer address, rent date, return date, fee paid

functional dependencies:

dvd number>>>>movie title

dvd number>>>>star

dvd number>>>>manufacture date

movie title>>>>star

movie title>>>>length

movie title>>>>year filmed

customer number>>>>customer name

customer number>>>>customer address

dvd number, customer number

rental date>>>>return date, fee paid

for each of the following tables, first write the table's current normal form (as 1nf,2nf,3nf). then, take those tables that are currently in 1nf or 2nf and reconstruct them as well structured 3nf tables. primary key attributes are in bold. do not assume any functional dependencies other than those shown.

a)movie title, star, length, year filmed

b)dvd number, customer number, rental date, customer name, return date, fee paid

c)dvd number, manufacture fate, movie title, star

d)movie title, customer number, star, length, customer name, customer address

e)dvd number, customer number, rental date, return date, fee paid

Explanation / Answer

a)

movie title,star,length,year filmed---

it is in 3nf no need to restructure the table.

b)

dvd number,customer number,rental date,customer name,return date ,fee paid

needs to be restructured as:-

customer number ,customer name,return date,fee paid

dvd number,customer number.rental date

c)

dvd number,manufacturer date,movie title(fk),star(fk)

this need not be restructured...as it's in 3nf.

d)

movie title,customer number,star, length,customer name,customer address

there exists dependencies which can be further divided as:

movie title,customer number,star, length

customer number,customer name,customer address

e)dvd number,customer number,rental data,return date,fee paid

there exits dependencies so it can be further subdivided as

dvd number,rental date,return date,fee paid

customer number,dvd number,rental date

so the given tables are in 3nf.

Related Questions

Navigate

• Browse (All)
• Browse V
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.