Task 1

Consider the following conceptual schema of an operational database owned by a multinational real estate company. The database contains information about the real estate properties offered for sale, owners of the properties, potential buyers who are interested in the properties, and real estate agents involved in the selling of the properties.

Whenever a property is put on the market by an owner, a description of the property is entered into an operational database. Whenever a property is purchased, its description is removed from an operational database.
The real estate company would like to create a data warehouse to keep information about the finalized real estate transactions, properties involved in the transactions, sellers/owners, and agents involved in the real estate transactions. The real estate company would like to use a data warehouse to implement the following classes of analytical applications.

(1) Find the total number of real estate properties sold per month, year, street, city, country, and agent involved.

(2) Find an average asked price of real estate properties sold per month, year, street, city, country, and agent involved.

(3) Find an average final price of real estate properties sold per month, year, street, city, country, and agent involved.

(4) Find an average period of time on the market of real estate properties sold per month, year, street, city, country, and agent involved.

(5) Find the total number of times each real estate property has been sold in a given period of time.

(6) Find the total number of buyers interested in purchases of real estate properties sold per day, month, year, street, city, country, and agent involved.

Task 2

An objective of this task is to create a conceptual schema of a sample data warehouse domain described below. Read and analyze the following specifications of a data warehouse domain.

A person is represented as either a patient or a medical worker or an administration worker. Medical and administration workers work in medical facilities that have a name, address, and possibly specialization. Each medical worker is described as a unique staff number at a facility, name, address, and phone number.

A patient visits a medical facility for the service of a health problem. Each service involves a patient, a medical worker, and an administration worker. The service can be a diagnosis, treatment, or checkup. A description and date of each service are recorded. Time spent on service and the costs are recorded as well.