Question
relation R(ABCD) has these dependencies {A → B, B →
C,C → D} and it is decomposed into three relations R1(AB) , R2(BC), AND R3(CD). State true or false if the decomposition is dependency preserving or not?Solution
The decomposition is dependency preserving. Because the union of all the functional dependencies from R1, R2 AND R3 is equal to the dependencies that are in relation R.
Statements:Â Â Â Â Â
No book is a pencil.
All books are boards.
All boards are dusters.
No eraser is a duster.
...
Statements:All circles are rectangles.
No rectangle is a square.
Conclusions:I. No square is a rectangle.
II. Some rectangles are...
Statements : Some eggs are chickens.
No chicken is a hen.
No hen is a pigeon.
Conclusions : I. Some eggs may be hens.
II....
Statements :
All sparrows are parrots.
No parrot is bird.
All birds are peacocks.
Conclusions:
I. Some birds are ...
Statements: Some cars are scooters.
      All scooters are bikes.
Conclusions: I. some cars are bikes.
   II. Some...
Statements:Some students are Rich.
No Rich is a teacher.
Conclusions:I. Some teacher are not Rich.
II. Some Rich are students.
Statements: All flowers are books.
All books are carpets.
Some carpets are keys.
Some keys are locks.
Conclusions:I. Some ke...
Statement:
At-least some chairs are tables.
A few tables are fans.
Only a few windows are tables.
All tables are doors.
Statement:Â
Some jeans are not shirt.
All shirts are pant.
Some pants are not blazers.
Conclusion:
I. Some blaze...
Statements:
Only a few passage is comprehension
A few comprehension is language
All language is story
Conclusions: ...
