1 What four main types of actions involve databases? Briefly discuss each. 2 Discuss the differences between database systems and information retrieval systems. 3 What is the difference between logical data independence and physical data independence? Which one is harder to achieve? Why? 4 What is the difference between the two-tier and three-tier client/server architectures? 5 Discuss the capabilities that should be provided by a DBMS. 6 What is the difference between a database schema and a database state? 7 Define the following terms: entity, attribute, attribute value, relationship instance, composite attribute, multi valued attribute, derived attribute, complex attribute, key attribute, value set (domain). 8 Why are duplicate tuples not allowed in a relation? 9 What is normalization ?