Skip to main content

Database/DBMS Interview Questions And Answers - Part XII.



56) What Is Fully Functional Dependency?

Answer: In a relation R, X and Y are attributes. X functionally determines Y. Subset of X should not functionally determine Y.
 In the above example marks is fully functionally dependent on student_no and course_no together and not on subset of {student_no, course_no}. This means marks cannot be determined either by student_no or course_no alone. It can be determined only using student_no and course_no together.
Hence marks is fully functionally dependent on {student_no, course_no}.


57) What Is Partial Dependency?

Answer: Attribute Y is partially dependent on the attribute X only if it is dependent on a subset of attribute X.

For example course_name, Instructor_name are partially dependent on composite attributes {student-no, course_no} because course_no alone defines course_name, Instructor_name.


58) What Is Transitive Dependency?

Answer: X, Y and Z are 3 attributes in the relation R. Transitive dependency describes a condition where X, Y, and Z are attributes of a relation such that if X → Y and Y → Z, then Z is transitively dependent on X via Y (provided that X is not functionally dependent on Y or Z).
For example, grade depends on marks and in turn marks depend on {student_no, course_no}, hence Grade depends fully transitively on {student_no & course_no}.


59) What Is A Trivial Functional Dependency?

Answer: A trivial functional dependency is a functional dependency of an attribute on a superset of itself.

A functional dependency R: X → Y is called trivial if Y is a subset of X.

For example: {Employee ID, Employee Address} --> {Employee Address} is trivial, here {Employee Address} is a subset of {Employee ID, Employee Address}.


60) What Is Multivalued Dependency?

Answer: A multivalued dependency is a constraint according to which the presence of certain rows in a table implies the presence of certain other rows.

For example, imagine a GELL PEN Maker company that manufactures many models of GELL PEN, but always makes both red and blue colors of each model.

If you have a table that contains the model name, color and year of each GELL PEN the company manufactures, there is a multivalued dependency in that table. If there is a row for a certain model name and year in blue, there must also be a similar row corresponding to the red version of that same GELL PEN.


ALSO CHECK THE BELOW FAQ's:

61) What Are The Steps Of Normalization?
62) What Is First (1st) Normal Form (1NF)?
63) What Is Second (2nd) Normal Form (2NF)?
64) What Is Third (3rd) Normal Form (3NF)?
65) What Is Boyce-Codd Normal Form (BCNF)? Also Define Multivalued Dependency?


66) What is Fourth (4th) Normal Form (4NF)?
67) What is Fifth (5th) Normal Form (5NF)?
68) What Are The Lossless Inference Rules For Functional Dependencies (FD's) Or State The Armstrong's Axioms?
69) What Is Domain-Key Normal Form (DKNF)?
70) Define Transaction? Explain Different States Of Transaction?

... Return To DBMS FAQ's Main Page.

... Return To HR Interview Questions With Answers Main Page.

Comments

Popular posts from this blog

Tell Me Something About Yourself - Interview Answers.

Try to introduce some of your most important employment-oriented skills as well as your education and accomplishments to the interviewer. Answer to this question is very important because it positions you for the rest of the interview . That's why this statement is often called the "Positioning Statement". One should take the opportunity to show his/her communication skills by speaking clearly and concisely in an organized manner. Since there is no right or wrong answer for this question hence it is important to appear friendly. YOUR ANSWERS CAN BE: 1) I am a person with strong interpersonal skills and have the ability to get along well with people . I enjoy challenges and looking for creative solutions to problems. 2) Besides the details given in my resume, I believe in character values, vision and action. I am quick in learning from mistakes. I am confident that the various tests that you have conducted will corroborate my competencies apti...

What Is (Are) Your Weakness (Weaknesses)? - Interview Answers

There’s a saying – “However small the thorn maybe it has the ability to pierce.” Never say you are a Workaholic, a Perfectionist, etc. because it sounds negative. Try to convert these negative biased qualities into positive ones. For Example, In   place of Workaholic you can say you are a hard worker and always willing to work for extra hours. In place of Perfectionist , you can say you are detail oriented and like to set high standard for work. “Try to specify your weakness as your strength and also highlight it as a benefit.” Your answers can be: 1) One of my weaknesses as I perceive is occasional compromise on time for quality and perfection. 2) I feel I am not very detail-oriented . I’m a person that wants accomplish as much as possible. I realized this hurts quality and therefore I‘m trying hard to find a balance between quality and quantity. 3) At times even when I need help, I try to solve my own problems instead of asking a co-worker who might know...

What Is (Are) Your Strengths? - Interview Answers

This is a simple and popular interview question. Generally people answer it in two ways. There are people who simply state their strength like “I am Young, Dynamic, Intelligent, Smart and so on…”. Such answer is neither right nor wrong but does not help u in any way also. Secondly there are peoples who state their strengths and explain them how he can use his strength for the job and industry. Do not simply state your strength. Everyone has some strength, all you need is to convert them into benefits. In short, try to advertise yourself by converting your features into strengths. “EVERYONE CLAIM THEY ARE HONEST, HARDWORKING, SMART AND SO ON….. BUT WITH AN EXAMPLE IT IS MUCH MORE BELIEVABLE.” Your answers can be : 1) I am a hard worker and because of this ability I can work for additional hours to accomplish my tasks.I am commitment oriented and hence I always enjoy the trust and confidence of my team mates which enables me to perform my duties very easily. 2) I am a...