You are part of a team developing a database for the ambulance service. Your database must track data on all personnel (name and phone number) who are working or have previously been a member of any ambulance station. You must also track each station (name, address) as well as record what personnel belong to a station. A paramedic (person who works in an ambulance) may only belong to one station, but retired paramedics remain recorded (just in case theyre needed) even though they are no longer associated with any stations.

The country is divided into areas (name, size, population), and each area is serviced by one station (although one station often controls multiple areas). Areas that are urban have the address of the nearest hospital recorded and those that are rural record the most useful landing strip (for emergency flights).

Consider designing a database for this problem. Which of the below are NOT sensible design decisions? (Select all that apply.)

	1.	Since each area can only have one station, we should include the station information in area to optimize performance through minimizing joins.
	2.	Since areas can be either urban or rural, we could use an isA relation. In this case urban and rural areas store different information (hospitals and landing strips respectively) which indicates that an isA relationship is the correct approach.
	3.	Paramedics may be retired. The information doesn't provide an alternative, but we could use a term such as "active" for those that are not retired. This means that we should use an isA relation between the three entities (the parent Paramedics and children Active and Retired). Because only active paramedics are associated with a station, that relationship connects to Active rather than Paramedics.
	4.	Since a paramedic can belong to only one station, a procedure that adds a paramedic to a station should first check to ensure that the paramedic isn't already related to another station. The insertion should fail rather than letting a paramedic be associated with two stations. We can instead model this by merging the relationship between paramedics and stations into the paramedic entity. By doing this we can avoid running the check, because setting the station for a paramedic would then automatically overwrite the previous station.
	5.	Assuming that we build in functionality to add in new areas (perhaps because of a later redistribution or in case the company using this software gets a contract with other areas), this will be a complex operation. Since every area needs to have a station associated with it we will need to add new stations before the areas that they control and would need to check for this in the procedure. We would also need two procedures; one for adding urban areas and one for adding rural ones, because those need different information.