Explain the difference between voluntary and required participation and minimal cardinality.

Here they want to know if this depicts a one-to-one, one-to-many, or many-to-many relationship. I could use some explanation of how this works because I'm still confused   BOOK and BOOK COPY  COURSE and COURSE-SECTION  COURSE-SECTION and ROOM  INSTRUCTOR and COURSE  ROOM and INSTRUCTOR

Is Data Model a positive or negative attribute?

Label each phrase as either interpretation sharing, projection sharing, or fact sharing. Note: each information sharing type is used once. Diesel is leaking from the ship onto the dock. Answer (circle one): interpretation sharing, projection sharing, fact sharing. There is a fire station near the diesel leak. Those firefighters have been trained to respond to small diesel spills. Answer (circle one): interpretation sharing, projection sharing, fact sharing. If the ship leaks more than 10,000 gallons of diesel, then we will need to send in additional firefighters and specialized equipment trucks through Route B. Answer (circle one): interpretation sharing, projection sharing, fact sharing.

What does it mean to have an attribute that is derived? I'd want to see an example of this. Do derived attributes have any advantages or disadvantages?