Theory Of Database Quiz 7 Act2b
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Choose the letter of the correct answer
Questions and Answers
- 1.
It is defined as the process of applying a series of techniques and rules to a database in order to reduce data redundancy
- A.
Normalization
- B.
Normal form
- C.
Projection
Correct Answer
A. NormalizationExplanation
Normalization is a process in database management that involves applying various techniques and rules to eliminate data redundancy. This helps in organizing and structuring the database efficiently, ensuring that each piece of data is stored in only one place. By doing so, normalization helps in improving data integrity, reducing storage space, and simplifying data retrieval and manipulation operations.Rate this question:
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- 2.
it is a description of the rules that a database at a certain level of normalization must follow
- A.
Normalization
- B.
Normal form
- C.
Projection
Correct Answer
B. Normal formExplanation
The given correct answer describes the concept of normal form in a database. Normalization refers to the process of organizing data in a database to eliminate redundancy and improve data integrity. Normal forms define a set of rules that a database must follow to ensure data is structured correctly. These rules help in reducing data duplication and inconsistencies, making the database more efficient and reliable. The term "projection" is unrelated to the concept of normal form and does not provide any relevant explanation.Rate this question:
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- 3.
it is defined as any attribute that does not participate in the primary key of the relation concerned
- A.
Key attribute
- B.
Mutual independence
- C.
Non-key attribute
- D.
Determinant
Correct Answer
C. Non-key attributeExplanation
A non-key attribute is any attribute that is not part of the primary key of a relation. In other words, it does not uniquely identify a tuple in the relation. Non-key attributes are not used to determine the values of other attributes in the relation and are independent of other attributes. They provide additional information about the tuples but are not essential for identifying them.Rate this question:
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- 4.
This condition exists among attributes within a relation if none of them are functionally dependent on any combination of the others
- A.
Key attribute
- B.
Non-key attribute
- C.
Determinant
- D.
Mutual independence
Correct Answer
D. Mutual independenceExplanation
Mutual independence refers to a condition in which none of the attributes within a relation are functionally dependent on any combination of the others. In other words, each attribute is independent and does not rely on any other attribute to determine its value. This ensures that there is no redundancy or unnecessary dependencies within the relation, leading to a more efficient and normalized database design.Rate this question:
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- 5.
If a table is in second normal form.
- A.
It is also in first normal form
- B.
It is also in third normal form
- C.
It does not contain any transitive dependencies
- D.
It contains attributes that are not fully functionally dependent on the key
Correct Answer
A. It is also in first normal formExplanation
If a table is in second normal form, it means that it has already satisfied the requirements of first normal form. First normal form states that all attributes in a table must contain only atomic values and there should be no repeating groups. Therefore, if a table is in second normal form, it is also in first normal form.Rate this question:
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- 6.
It is a normal form that states that all underlying simple domains contain atomic values only
- A.
3NF or Third Normal Form
- B.
2NF or second normal form
- C.
1NF or First normal form
- D.
Normalization
Correct Answer
C. 1NF or First normal formExplanation
The given correct answer is 1NF or First normal form. This is because 1NF is the basic level of normalization and it states that all underlying simple domains contain atomic values only. In other words, each attribute in a relation must have a single value, and there should be no repeating groups or arrays of values. This helps to eliminate redundancy and ensures that the data is organized efficiently.Rate this question:
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- 7.
If a table is in third normal form
- A.
It is also in Boyce-Codd normal form
- B.
It contains non-atomic attributes
- C.
It does not contain any transitive dependencies
- D.
It contains attributes that are not fully functionally dependent on the key
Correct Answer
C. It does not contain any transitive dependenciesExplanation
If a table is in third normal form, it means that it has already met the requirements of the first and second normal forms. Third normal form specifically states that the table should not contain any transitive dependencies. Transitive dependency occurs when an attribute depends on another attribute, which in turn depends on another attribute. By eliminating transitive dependencies, the table is better organized and reduces redundancy and potential update anomalies. Therefore, if a table is in third normal form, it does not contain any transitive dependencies.Rate this question:
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- 8.
It is a normal form that states that every nonkey attribute is fully dependent on the primary key.
- A.
3NF or Third Normal Form
- B.
2NF or second normal form
- C.
1NF or First normal form
- D.
Normalization
Correct Answer
B. 2NF or second normal formExplanation
The given correct answer is 2NF or second normal form. In second normal form, every nonkey attribute is fully dependent on the primary key. This means that all attributes in a table should depend on the entire primary key, and not just part of it. In other words, there should be no partial dependencies where an attribute depends on only a portion of the primary key. This helps to eliminate redundancy and improve data integrity in a database.Rate this question:
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- 9.
It is a normal form if and only if every determinant is a candidate key
- A.
3NF or Third Normal Form
- B.
2NF or second normal form
- C.
1NF or First normal form
- D.
BCNF or Boyce-Codd normal form
Correct Answer
D. BCNF or Boyce-Codd normal formExplanation
BCNF or Boyce-Codd normal form is the correct answer because it states that a relation is in BCNF if and only if every determinant is a candidate key. This means that in a BCNF relation, there are no non-trivial functional dependencies where the determinant is not a candidate key. BCNF is a higher normal form than 3NF and 2NF, and it ensures that there are no redundancy or update anomalies in the relation.Rate this question:
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- 10.
It is a normal form if and only if it is in 2NF and every non-key attribute is nontransitively dependent on the primary key.
- A.
3NF or Third Normal Form
- B.
2NF or second normal form
- C.
1NF or First normal form
- D.
Normalization
Correct Answer
A. 3NF or Third Normal FormExplanation
A relation is in 3NF if it is already in 2NF and every non-key attribute is nontransitively dependent on the primary key. This means that there are no transitive dependencies between non-key attributes. In other words, if attribute A depends on attribute B, and attribute B depends on the primary key, then attribute A should also depend directly on the primary key. This ensures that the relation is free from redundancy and anomalies, making it in the highest level of normalization.Rate this question:
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Jan 22, 2024Quiz Edited by
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Feb 21, 2010Quiz Created by
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