For a library, the entity type HOLDING has three subtypes: BOOK, AUDIO BOOK and DVD. Draw a separate EER diagram segment for each of the following situations:
a. At a given time, a holding must be at least one of these subtypes.
b. At a given time, a holding must be exactly one of these subtypes.
c. A holding may or may not be one of these subtypes. Also, a holding may be any two or three of these subtypes at the same time.
Question 2 (11 pts)
Draw an EER diagram for the following problem. Make sure all cardinalities are represented. If the information provided are not enough, state any assumptions that you have made while drawing your diagram. A company posts job opening online. Job seekers must apply for these jobs online as well. The company has a strict policy that only one job application is allowed for each job seeker. Job openings usually have several applicants, but it is possible for some opening to have no applicant. Only job seekers who applied for a job opening are saved in the database. Job seekers have a unique ID number, a name, an address, a work history and qualifications. A job posting must be either for a part-time or full-time position and those two position types are distinct from each other. Part-time positions have a total number of weekly hours and an hourly rate. Full-time positions have a monthly salary. Both types of job listings have details about the position title, and experience required as well as a unique job opening ID. For some, but not all, of the full-time job openings, the company ask recruiting agencies to take care of the hiring and interview process. The company works with several recruiting agencies, and keep information about the agency name, contact person name and phone number, in addition to an assigned agency identification number. While a recruiting agency must be in charge of several full-time job openings, each full-time job opening can be assigned to only one agency until the position is filled.