We can convert any weak entity set to a strong entity set by simply adding appropriate attributes.Why, then, do we have weak entity sets?
Answer to relevant QuestionsDefine the concept of aggregation. Give two examples of where this concept is useful.In Section 2.4.3, we represented a ternary relationship (Figure a) using binary relationships, as shown in (Figure b). Consider the alternative shown in (Figure c). Discuss the relativemerits of these two alternative ...Figure shows a lattice structure of generalization and specialization. For entity sets A, B, and C, explains how attributes are inherited from the higherlevel entity sets X and Y. Discuss how to handle a case where an ...Consider the relational database of Figure, where the primary keys are underlined. Give an expression in the relational algebra to express each of the following queries:a. Find the names of all employees who work for First ...Let R = (A, B, C), and let r1 and r2 both be relations on schema R. Give an expression in the domain relational calculus that is equivalent to each of the following: a. IIA(r1) b. σB =17 (r1) c. r1 ∪ r2 d. r1 ...
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