... customer_name a) difference, selection, projection b) difference, direct product, selection c) direct product, selection, projection d) union, direct product, projection Q35 Which of the following ... precision ratio used as measures in evaluating information retrieval systems, such as document retrieval systems and data retrieval systems? Here, A, B and C indicate the following. A: The ... form normal form normalized Q28 How many different projections are there of a relation which has n attributes? Here, the number of projections includes those with the same result as the...