Questions 5.3 and 5.4

. In the domain relational calculus, domain variables take their values from domains of attributes tuples of relations. . The relational algebra is logically equivalent to a safe subset of the relational calculus (and vice versa). . Relational data manipulation languages are sometimes classified as procedural or nonprocedural, transform oriented, graphical, fourth-generation, or fifth-generation Review Questions 5.1 What is the difference between a procedural and a nonprocedural language? How would you classify the relational algebra and relational calculus? 5.2 Explain the following terms: (a) relationally complete 5.3 Define the five basic relational algebra operations. Define the Join, Intersection, and Division operations in terms of 5.4 Discuss the differences between the five Join operations: Theta join, Equijoin, Natural join, Outer join, and Semi- 5.5 Compare and contrast the tuple relational calculus with domain relational calculus. In particular, discuss the distinc- 5.6 Define the structure of a (well-formed) formula in both the tuple relational calculus and domain relational calculus. (b) closure of relational operations. these five basic operations. join. Give examples to illustrate your answer. tion between tuple and domain variables. 5.7 Explain how a relational calculus expression can be unsafe. Illustrate your answer with an example. Discuss how to ensure that a relational calculus expression is safe