Applying normalisation to 3NF on the table shown in Figure 14.23 results in the formation of the four tables shown in Figure 14.24.
(a) Identify the functional dependencies that exist between the columns of each table in Figure 14.24 and identify the primary key and any alternate and foreign key(s) (if present) for each table.
(b) Describe why storing the university accommodation data across four 3NF tables avoids the update anomalies described in Exercise 14.19(b).
(c) Describe how the original table shown in Figure 14.23 can be re-created through relational joins between primary key and foreign keys columns of the tables in Figure 14.24.
Exercise 14.19
Students can lease university flats and some of the details of leases held by students for places in university flats are shown in Figure 14.23. A place number (placeNo) uniquely identifies each single room in all flats and is used when leasing a room to a student.
(a) Identify the functional dependencies that exist between the columns of the table in Figure 14.23 and identify the primary key and any alternate key(s) (if present) for the table.
(b) Describe why the table in Figure 14.23 is not in 3NF.
(c) The table shown in Figure 14.23 is susceptible to update anomalies. Provide examples of how insertion, deletion, and modification anomalies could occur on this table.
Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.
You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.
Read moreEach paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.
Read moreThanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.
Read moreYour email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.
Read moreBy sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.
Read more