a. Give a concrete example of something you can do with ER diagrams you can not do in the relational model. Be specific.

b. True or False: Hash tables pseudo-randomly map elements from a small domain to a large domain

c. A car company has a large database about their customers. This includes the following fields: name, address, car model, month/year of manufacture, the cost to produce, profit from the sale. The company has realized that all cars manufactured in the last 8 months have a faulty part and so the company wants to issue a recall. The recall notice will be sent to the car buyers at their address in the database. Explain which indexing scheme, i.e. hash table or B+ Tree, you would use on what key, and what you would return. Justify your answer.

d. Explain a situation when using a hash function for data that CAN be naturally ordered would make sense.