9618/12

Computer Science 9618/12May/June 2021

Cambridge AS Level · Theory Fundamentals · worked solutions for every part, with the mark scheme

8
questions
75
marks
90
minutes

Topics Processor Fundamentals · Information Representation · Databases · Ethics and Ownership · Hardware · Communication · +2 more

Q1DatabasesFree sample

Raj owns houses that other people rent from him. He has a database that stores details about the people who rent houses, and the houses they rent. The database, HOUSE_RENTALS, has the following structure:

CUSTOMER(CustomerID, FirstName, LastName, DateOfBirth, Email)
HOUSE(HouseID, HouseNumber, Road, Town, Bedrooms, Bathrooms)
RENTAL(RentalID, CustomerID, HouseID, MonthlyCost, DepositPaid)

(a)

Give the definition of the following database terms, using an example from the database HOUSE_RENTALS for each definition.

TermDefinition and example
Field
Entity
Foreign key
6M
(b)

Tick (✓) one box to identify whether the database HOUSE_RENTALS is in Third Normal Form (3NF) or not in 3NF.
Justify your choice using one or more examples from the database HOUSE_RENTALS.

In 3NF
Not in 3NF

Justification ...............................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

.............................................................................................................................................

2M
(c)

Example data from the table RENTAL are given:

RentalIDCustomerIDHouseIDMonthlyCostDepositPaid
12215B5L1000.00Yes
2133F687.00No
3112AB550.00Yes
4337444.50Yes
(i)

Complete the following Data Definition Language (DDL) statement to define the table RENTAL.

CREATE ...................................... ...................................... (
    RentalID INTEGER NOT NULL,
    CustomerID INTEGER NOT NULL,
    HouseID ...................................... (5) NOT NULL,
    MonthlyCost ...................................... NOT NULL,
    DepositPaid BOOLEAN NOT NULL,
    .......................................................... (RentalID)
);
4M
(ii)

Write a Data Manipulation Language (DML) script to return the first name and last name of all customers who have not paid their deposit.

4M

The rest of this paper

7 more questions
  • Q2Ethics and Ownership9M
  • Q3Hardware6M
  • Q4Processor Fundamentals · Information Representation8M
  • Q5Processor Fundamentals · Communication17M
  • Q6Information Representation6M
  • Q7System Software8M
  • Q8Security, Privacy and Data Integrity5M
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