Database Management System
Q51.
In a schema with attributes A, B, C, D and E following set of functional dependencies are given A \rightarrow B A \rightarrow C CD \rightarrow E B \rightarrow D E \rightarrow A Which of the following functional dependencies is NOT implied by the above set?Q52.
A table has fields F_1, F_2, F_3, F_4, F_5 with the following functional dependencies F_1 \to F_3, F_2\to F_4, (F_1 . F_2) \to F_5 In terms of Normalization, this table is inQ53.
Consider the following functional dependencise in a database: Data_of_Birth \rightarrow Age Age \rightarrow Eligibility Name \rightarrow Roll_number Roll_number \rightarrow Name Course_number \rightarrow Course_name Course_number \rightarrow Instructor (Roll_number, Course_number) \rightarrow Grade The relation (Roll_number,Name,Date_of_brith,Age) isQ54.
A relation Empdtl is defined with attributes empcode (unique), name, street, city, state and pincode. For any pincode, there is only one city and state. Also, for any given street, city and state, there is just one pincode. In normalization terms, Empdtl is a relation inQ55.
Relation R is decomposed using a set of functional dependencies, F ,and relation S is decomposed using another set of functional dependencies, G. One decomposition is definitely BCNF , the other is definitely. 3NF , but it is not known which is which. To make a guaranteed identification, which one of the following tests should be used on the decompositions ? (Assume that the closures of F and G are available).Q56.
The relation scheme Student Performance (name, courseNo, rollNo, grade) has the following functional dependencies: name, courseNo, \rightarrow grade rollNo, courseNo \rightarrow grade name \rightarrow rollNo rollNo \rightarrow name The highest normal form of this relation scheme isQ58.
Consider the following entity relationship diagram (ERD), where two entities E1 and E2 have a relation R of cardinality 1:m.The attributes of E1 are A11, A12 and A13 where A11 is the key attribute. The attributes of E2 are A21, A22 and A23 where A21 is the key attribute and A23 is a multi-valued attribute. Relation R does not have any attribute. A relational database containing minimum number of tables with each table satisfying the requirements of the third normal form (3NF) is designed from the above ERD. The number of tables in the database isQ59.
Given the following relation instance. \begin{array}{|l|l|l|}\hline \text{X} & \text{Y} & \text{Z} \\\hline \text{1} & \text{4} & \text{2} \\ \text{1} & \text{5} & \text{3} \\ \text{1} & \text{6} & \text{3} \\ \text{3} & \text{2} & \text{2} \\\hline \end{array}Which of the following functional dependencies are satisfied by the instance?Q60.
Consider the schema R=(S,T, U, V) and the dependencies S \rightarrow T, T \rightarrow U, U \rightarrow V and V \rightarrow S. Let R = (R1\text{ and } R2) be a decomposition such that R1 \cap R2 \neq \phi. The decomposition is