Assignment: Client bookings for taxis.

Assignment: Client bookings for taxis.

14.17 – A company called FastCabs provides a taxi service to clients. The table shown in Figure 14.21 displays some details of client bookings for taxis. Assume that a taxi driver is assigned to a single taxi, but a taxi can be assigned to one or more drivers.

A) Identify the functional dependencies that exist between the columns of the table in Figure 14.21 and identify the primary key and any alternate key(s) (if present) for the table.

B) Describe why the table in Figure 14.21 is not in 3NF.

C) The table shown in Figure 14.21 is susceptible to update anomalies. Provide examples of how insertion, deletion, and modification anomalies could occur on this table.

(Figure 14.21 – Table displaying sample data for FastCabs.)

14.18 – Applying normalization to 3NF on the table shown in Figure 14.21 results in the formation of the three 3NF tables shown in Figure 14.22.

A) Identify the functional dependencies that exist between the columns of each table in Figure 14.22 and identify the primary key and any alternate and foreign key(s) (if present) for each table.

B) Describe why storing the FastCabs data across the 3NF tables avoids the update anomalies described in Exercise 14.17(B).

C) Describe how the original table shown in Figure 14.21 can be re-created through relational joins between primary key and foreign keys columns of the tables in Figure 14.22.

(Figure 14.22 – Tables (in 3NF) displaying sample data for FastCabs.)

Use the information in the figure below to answer the following questions. (The sample data may not represent all future field values; use common knowledge and consider the domain for each field).

We record only the last sale for each car. For each sale, a car can be sold to only one customer; however, each customer can buy (own) more than one car.

Include the below numbers to organize the submission. DO NOT include the Questions ot other content from the instructions in your answer.

1) Describe functional dependency only; NOT full functional dependency, or partial dependency. While you may incorporate the formal definition, you must explain the concept in your own words, using field names and values from this exercise.

2) Identify the primary key for the table in the above figure. Indicate whether there are any alternate keys (for this table). Explain each of the choices.

3) Is the table in 3NF? If not, explain why – (provide specific rational, use field names and values in the table to demonstrate understanding). Explain what normal form the table provided is in.

You must proofread your paper. But do not strictly rely on your computer’s spell-checker and grammar-checker; failure to do so indicates a lack of effort on your part and you can expect your grade to suffer accordingly. Papers with numerous misspelled words and grammatical mistakes will be penalized. Read over your paper – in silence and then aloud – before handing it in and make corrections as necessary. Often it is advantageous to have a friend proofread your paper for obvious errors. Handwritten corrections are preferable to uncorrected mistakes.

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The paper must be neatly formatted, double-spaced with a one-inch margin on the top, bottom, and sides of each page. When submitting hard copy, be sure to use white paper and print out using dark ink. If it is hard to read your essay, it will also be hard to follow your argument.