Q. There are two functional dependencies with the same set of attributes on the left side of the arrow:

A->BC
A->B

This can be combined as

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Q. Consider a relation R(A,B,C,D,E) with the following functional dependencies:

ABC -> DE and
D -> AB

The number of superkeys of R is:

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Q. Suppose we wish to find the ID’s of the employees that are managed by people who are managed by the employee with ID 123. Here are two possible queries:

I.SELECT ee.empID

FROM Emps ee, Emps ff

WHERE ee.mgrID = ff.empID AND ff.mgrID = 123;

II.SELECT empID

FROM Emps

WHERE mgrID IN

(SELECT empID FROM Emps WHERE mgrID = 123);

Which, if any, of the two queries above will correctly (in SQL2) get the desired set of employee ID’s?

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Q. Suppose relation R(A,B) currently has tuples {(1,2), (1,3), (3,4)} and relation S(B,C) currently has {(2,5), (4,6), (7,8)}. Then the number of tuples in the result of the SQL query:

SELECT *
FROM R NATURAL OUTER JOIN S;

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Q. Suppose now that R(A,B) and S(A,B) are two relations with r and s tuples, respectively (again, not necessarily distinct). If m is the number of (not necessarily distinct) tuples in the result of the SQL query:

R intersect S;

Then which of the following is the most restrictive, correct condition on the value of m?

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Q. Suppose relation R(A,B,C,D,E) has the following functional dependencies:
A -> B

B -> C

BC -> A

A -> D

E -> A

D -> E

Which of the following is not a key?

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Q. The normal form which satisfies multivalued dependencies and which is in BCNF is

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Q. Which of the following is a tuple-generating dependencies ?

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Q. The main task carried out in the __________ is to remove repeating attributes to separate tables.

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Q. Which of the normal form is based on multivalued dependencies ?

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Q. Which forms has a relation that possesses data about an individual entity?

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Q. If a multivalued dependency holds and is not implied by the corresponding functional dependency, it usually arises from one of the following sources.

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Q. Which of the following has each related entity set has its own schema and there is an additional schema for the relationship set?

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Q. In which of the following , a separate schema is created consisting of that attribute and the primary key of the entity set.

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Q. Fifth Normal form is concerned with

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Q. In 2NF

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Q. _____________ can help us detect poor E-R design.

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Q. Which of the following has each related entity set has its own schema and there is an additional schema for the relationship set.

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Q. Suppose the user finds the usage of room number and phone number in a relational schema there is confusion.This is reduced by

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Q. What is the best way to represent the attributes in a large database?

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