NIELIT 2017 DEC Scientist B - Section B: 1

Question

Which one of the following statements are not correct?

$S1$: $3$NF decomposition is always lossless join and dependency preserving.

$S2$: $3$NF 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.

• A. Only $S1$
• B. Only $S4$
• C. Both $S1$ and $S4$
• D. Both $S2$ and $S3$

Comments

option D

Answer 1

• ANS : D
• 3NF decomposition is always lossless join and dependency preserving.
• BCNF decomposition is always lossless join but may or may not be dependency preserving.SO,