adplus-dvertising
frame-decoration

Question

If a functional dependency is reflexive, B is a subset of A and A is the set of attributes, then

a.

B→A holds

b.

A→B holds

c.

AB→C holds

d.

None of the mentioned

Posted under DBMS

Answer: (b).A→B holds

Engage with the Community - Add Your Comment

Confused About the Answer? Ask for Details Here.

Know the Explanation? Add it Here.

Q. If a functional dependency is reflexive, B is a subset of A and A is the set of attributes, then

Similar Questions

Discover Related MCQs

Q. State true or false: Armstrong’s axioms allow us to generate all F+ for any given F

Q. Armstrong axioms are called sound because?

Q. State true or false: Functional dependencies are transitive

Q. If A→B, A→ C then which of the following is true?

Q. If B is an attribute and A→B, Then B is said to be ________ by a.

Q. We say that a decomposition having the property F’+ = F+ is a __________ decomposition.

Q. A _________ Fc for F is a set of dependencies such that F logically implies all dependencies in Fc, and Fc logically implies all dependencies in F.

Q. What does the BCNF decomposition algorithm do?

Q. The 3NF decomposition algorithm is also called as _______

Q. Which of the following is desirable in a database design with functional dependencies?

Q. Which of the following is not a process of generating a good relational schema?

Q. What is unique role assumption?

Q. The process of making a normalized schema unnormalized is called as _________

Q. State true or false: Crosstabs are not desirable in a database design

Q. The data that have a time interval associated with them during which they are valid are called as ________

Q. The value of the data at a particular time is called as?

Q. Functional dependencies that have a time associated with them during which they are valid are called as________

Q. State true or false: Overlapping time intervals cannot be prevented

Q. Which of the following is the time of temporal data that record when a fact was recorded in a database?

Q. To specify the foreign keys in relations referencing temporal data we need to specify _______