Exam questions

2021 02 04 Q1

A maintenance and service management company supports public administrations in the management of public properties (parks, streets, and so on). The company needs to record the notification of maintenance needs and how they are addressed. Citizens can submit issues in the system which can be of different types (urgent maintenance, cleaning services, damage repair), and are described by a title, city, address, and description, possibly including photos. City administrators can review the notifications and approve them. Approved ones need to be addressed, therefore the company assigns a maintenance team to the issue and assigns a schedule for the operations. The team may be composed of employees, including a team leader plus one or more team members, plus a set of vehicles and of devices (cleaning machines, lawn mowers, and so on). At the end, a report on the work done is filed into the system. Information about the employees, vehicles and devices is stored in the system.

1. Describe the data at high level showing a conceptual model, for instance an ER model. (2)
2. Explain if and how you could use a key-value DB for the problem. Which parts/elements could be covered by a key-value solution? Describe which key you would use for each element. (2)
3. Write a command that adds a new citizen in the DB and a command that retrieves its data from the DB (you may assume you can use any key-value technology you like). (1)