July2016 cs Q10

0. Which of the following statements is TRUE?
D₁ : The decomposition of the schema R(A, B, C) into R₁(A, B) and R₂ (A, C) is always lossless.
D₂ : The decomposition of the schema R(A, B, C, D, E) having
AD → B,
C → DE,
B → AE and
AE → C,
into R₁ (A, B, D) and R₂ (A, C, D, E) is lossless.

Answer
Comment
Array

Option : D
Explanation :
only D₂ is True because AD is key and present in both the tables. D₁ is not always true because FD’s not given and if we take B->A and C->Athen it is lossy decomposition because no common attributes contain key from one of the table.

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