Question 1 |

In a relational data model, which one of the following statements is TRUE?

A relation with only two attributes is always in BCNF. | |

If all attributes of a relation are prime attributes, then the relation is in BCNF. | |

Every relation has at least one non-prime attribute. | |

BCNF decompositions preserve functional dependencies. |

Question 1 Explanation:

Question 2 |

Suppose the following functional dependencies hold on a relation U with attributes P, Q, R, S, \text{ and } T:

P \rightarrow QR \\ RS \rightarrow T

Which of the following functional dependencies can be inferred from the above functional dependencies?

P \rightarrow QR \\ RS \rightarrow T

Which of the following functional dependencies can be inferred from the above functional dependencies?

**[MSQ]**PS \rightarrow T | |

R \rightarrow T | |

P \rightarrow R | |

PS \rightarrow Q |

Question 2 Explanation:

Question 3 |

If every non-key attribute functionally dependent on the primary key, then the relation will be in

First normal form | |

Second normal form | |

Third normal form | |

Fourth Normal form |

Question 3 Explanation:

Question 4 |

Consider a relational table R that is in 3NF, but not in BCNF. Which one of the following statements is TRUE?

R has a nontrivial functional dependency X\rightarrow A, where X is not a superkey and A is a prime attribute. | |

R has a nontrivial functional dependency X\rightarrow A, where X is not a superkey and A is a non-prime attribute and X is not a proper subset of any key. | |

R has a nontrivial functional dependency X\rightarrow A, where X is not a superkey and A is a non-prime attribute and X is a proper subset of some key. | |

A cell in R holds a set instead of an atomic value. |

Question 4 Explanation:

Question 5 |

Let the set of functional dependencies F=\{QR\rightarrow S,R\rightarrow P,S\rightarrow Q\} hold on a relation schema X = (PQRS). X is not in BCNF. Suppose X is decomposed into two schemas Y and Z where Y = (PR) and Z = (QRS).

Consider the two statements given below:

I. Both Y and Z are in BCNF

II. Decomposition of X into Y and Z is dependency preserving and lossless.

Which of the above statements is/are correct?

Consider the two statements given below:

I. Both Y and Z are in BCNF

II. Decomposition of X into Y and Z is dependency preserving and lossless.

Which of the above statements is/are correct?

Both I and II | |

I only | |

II only | |

Neither I nor II |

Question 5 Explanation:

There are 5 questions to complete.

Sir, Please check question number 24. Half question is something else, and half is something else.

Thank You Ashutosh,

We have updated the question.

Ques 2’s answer should be option c. kindly check and confirm.

https://www.geeksforgeeks.org/isro-isro-cs-2020-question-65/

Answer is (B) only. You can check the details solution.

In Question Number 34, there is printing mistake in ( A→→BC )

The correct option is : i) if A→→B and A→→C then A→BC

Thank You Rashmi,

We have updated the option. It is question no 28.

Question 45.

3rd option is:-

AB→C, C→AD

Please update it ;-).

In question number 24 there is a problem in defining relational schema.

plz correct 46 it is a msq