2. (10%) Consider the ER diagram below for modeling an online bookstore. a. (6%) Translate the ER diagram into a relational model. b. (2%) Provide the Tuple Relational Calculus expression for the following query: "List the names of all books published in the year 2020, by 'Wiley' publisher. " c. (2%) Provide the Relational Algebra expression for the following query: "Find the names of all books with price lower than $50 that are stored in the warehouse with code '556677'." 3. (10%) Consider a relation with schema R (A, B, C, D) and the set F of functional dependencies: F= { ABrC , CrD . D>A} a. (2%) Find all the candidate keys of R. b. (4%) Indicate all BCNF violations for R and decompose the relations into collections of relations that are in BCNF. c. (4%) indicate which dependencies, if any, are not preserved by the BCNF decomposition