CIS 223 Unit 2 Lab Assignment 1 3
1. What is the difference between a database and a table?
2.What does it mean to say that a database displays both entity integrity and referential integrity?
3.Why are entity integrity and referential integrity important in a database?
4. What are the requirements that two relations must satisfy to be considered union-compatible?
5.Which relational algebra operators can be applied to a pair of tables that are not union-compatible?
6.Explain why the data dictionary is sometimes called “the database designer’s database.”
Suppose you have the ERM shown in Figure Q3.14. How would you convert this model into an ERM that displays only 1:M relationships? (Make sure you create the revised ERM.) Refer to the table in this attachment.