Question: Given the database schema R a b c and a relation r on the
Given the database schema R (a, b, c), and a relation r on the schema R, write an SQL query to test whether the functional dependency b → c holds on relation r. Alsowrite an SQL assertion that enforces the functional dependency. Assume that no null values are present.
Relevant QuestionsShow that the following decomposition of the schema R of Exercise 7.2 is not loss less-join decomposition:(A, B, C)(C, D, E).Give a loss less-join decomposition into BCNF of schema R of Exercise 7.2.Give an example of a relation schema R and a set of dependencies such that R is in BCNF, but is not in 4NF.Explain the distinction in meaning between edges in a DAG representing inheritance and a DAG representing object containment.Redesign the database of Exercise 9.1 into first normal form and fourth normal form. List any functional or multivalued dependencies that you assume. Also list all referential-integrity constraints that should be present in ...
Post your question