UGC NET CS 2005 Dec-Paper-2
November 5, 2023Question 1783 – Nielit Scientist-B 17-12-2017
November 5, 2023Database-Management-System
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Question 745
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Which of the following statements are not correct?
S1: 3NF decomposition is always lossless join and dependency preserving
S2: 3NF decomposition is always lossless join but may or may not be dependency preserving
S3: BCNF decomposition is always lossless join and dependency preserving
S4: BCNF decomposition is always lossless join but may or may not be dependency preserving
S1: 3NF decomposition is always lossless join and dependency preserving
S2: 3NF decomposition is always lossless join but may or may not be dependency preserving
S3: BCNF decomposition is always lossless join and dependency preserving
S4: BCNF decomposition is always lossless join but may or may not be dependency preserving
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Only S1
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Only S4
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boh S1 and S4
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Both S2 and S3
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Question 745 Explanation:
→ Sometimes, BCNF may not be functional dependency preserving.
→ lossless join should be compulsory in any normal form.
→ lossless join should be compulsory in any normal form.
Correct Answer: D
Question 745 Explanation:
→ Sometimes, BCNF may not be functional dependency preserving.
→ lossless join should be compulsory in any normal form.
→ lossless join should be compulsory in any normal form.