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Consider the following dependencies in a database
D → A A → E
N → R R → N
C → C → I
(R, C) → G
The relation (R, N, D, A) is
- a)in BCNF
- b)in 3NF but not in BCNF
- c)IN 1NF but not in 2NF.Correct Answer
- d)None of these
Correct answer is option 'C'. Can you explain this answer?
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Verified Answer
Consider the following dependencies in a databaseD → A A → E...
D →A A → E
N →R R → N
C → C →I
(R, C) →G
From the given relation
R( R, N, D, A)
The functional dependencies which this particular relation hold:
D →A N →R R → N
The candidate key for the relation will be: RD, DN
Hence partial dependency exists in the given relation R:
D →A
So relation is in 1NF but not in 2NF.
Most Upvoted Answer
Consider the following dependencies in a databaseD → A A → E...
Understanding the Given Functional Dependencies
The functional dependencies provided are:
- D → A
- A → E
- N → R
- R → NC
- C → I
- (R, C) → G
These dependencies help us analyze the normalization levels of the relation (R, N, D, A).
1NF, 2NF, and 3NF Concepts
- 1NF (First Normal Form): A relation is in 1NF if it contains only atomic values and each entry in a column is of the same kind.
- 2NF (Second Normal Form): A relation is in 2NF if it is in 1NF and all non-key attributes are fully functionally dependent on the primary key.
- 3NF (Third Normal Form): A relation is in 3NF if it is in 2NF and no transitive dependencies exist.
Analyzing the Relation (R, N, D, A)
- The primary key here can be assumed as (R, N) based on the functional dependencies.
- D is dependent on R, and A is dependent on D. Thus, A is transitively dependent on (R, N), violating 3NF.
- Since the relation is in 1NF (all attributes are atomic), it satisfies the criteria for 1NF.
Conclusion: Why Option 'C' is Correct
- The relation (R, N, D, A) is in 1NF because it holds atomic values.
- However, it does not satisfy 2NF due to the partial dependency of A on D, which is not a candidate key.
- Therefore, the relation is in 1NF but not in 2NF.
This leads us to conclude that the correct answer is option 'C': IN 1NF but not in 2NF.
The functional dependencies provided are:
- D → A
- A → E
- N → R
- R → NC
- C → I
- (R, C) → G
These dependencies help us analyze the normalization levels of the relation (R, N, D, A).
1NF, 2NF, and 3NF Concepts
- 1NF (First Normal Form): A relation is in 1NF if it contains only atomic values and each entry in a column is of the same kind.
- 2NF (Second Normal Form): A relation is in 2NF if it is in 1NF and all non-key attributes are fully functionally dependent on the primary key.
- 3NF (Third Normal Form): A relation is in 3NF if it is in 2NF and no transitive dependencies exist.
Analyzing the Relation (R, N, D, A)
- The primary key here can be assumed as (R, N) based on the functional dependencies.
- D is dependent on R, and A is dependent on D. Thus, A is transitively dependent on (R, N), violating 3NF.
- Since the relation is in 1NF (all attributes are atomic), it satisfies the criteria for 1NF.
Conclusion: Why Option 'C' is Correct
- The relation (R, N, D, A) is in 1NF because it holds atomic values.
- However, it does not satisfy 2NF due to the partial dependency of A on D, which is not a candidate key.
- Therefore, the relation is in 1NF but not in 2NF.
This leads us to conclude that the correct answer is option 'C': IN 1NF but not in 2NF.
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Consider the following dependencies in a databaseD → A A → EN → R R → NC → C → I(R, C) → GThe relation (R, N, D, A) isa)in BCNFb)in 3NF but not in BCNFc)IN 1NF but not in 2NF.Correct Answerd)None of theseCorrect answer is option 'C'. Can you explain this answer?
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Consider the following dependencies in a databaseD → A A → EN → R R → NC → C → I(R, C) → GThe relation (R, N, D, A) isa)in BCNFb)in 3NF but not in BCNFc)IN 1NF but not in 2NF.Correct Answerd)None of theseCorrect answer is option 'C'. Can you explain this answer? for GATE 2024 is part of GATE preparation. The Question and answers have been prepared according to the GATE exam syllabus. Information about Consider the following dependencies in a databaseD → A A → EN → R R → NC → C → I(R, C) → GThe relation (R, N, D, A) isa)in BCNFb)in 3NF but not in BCNFc)IN 1NF but not in 2NF.Correct Answerd)None of theseCorrect answer is option 'C'. Can you explain this answer? covers all topics & solutions for GATE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Consider the following dependencies in a databaseD → A A → EN → R R → NC → C → I(R, C) → GThe relation (R, N, D, A) isa)in BCNFb)in 3NF but not in BCNFc)IN 1NF but not in 2NF.Correct Answerd)None of theseCorrect answer is option 'C'. Can you explain this answer?.
Consider the following dependencies in a databaseD → A A → EN → R R → NC → C → I(R, C) → GThe relation (R, N, D, A) isa)in BCNFb)in 3NF but not in BCNFc)IN 1NF but not in 2NF.Correct Answerd)None of theseCorrect answer is option 'C'. Can you explain this answer? for GATE 2024 is part of GATE preparation. The Question and answers have been prepared according to the GATE exam syllabus. Information about Consider the following dependencies in a databaseD → A A → EN → R R → NC → C → I(R, C) → GThe relation (R, N, D, A) isa)in BCNFb)in 3NF but not in BCNFc)IN 1NF but not in 2NF.Correct Answerd)None of theseCorrect answer is option 'C'. Can you explain this answer? covers all topics & solutions for GATE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Consider the following dependencies in a databaseD → A A → EN → R R → NC → C → I(R, C) → GThe relation (R, N, D, A) isa)in BCNFb)in 3NF but not in BCNFc)IN 1NF but not in 2NF.Correct Answerd)None of theseCorrect answer is option 'C'. Can you explain this answer?.
Solutions for Consider the following dependencies in a databaseD → A A → EN → R R → NC → C → I(R, C) → GThe relation (R, N, D, A) isa)in BCNFb)in 3NF but not in BCNFc)IN 1NF but not in 2NF.Correct Answerd)None of theseCorrect answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for GATE.
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