Related examples on mode decomposition: i.e., determines whether an exploded connection remains intact , and if the holding function dependent ;
Topic Source: MOOC network - war Dechen database courses
Reference Video: Principle B station Zhejiang University Chen Ling database system
1. The mode given relation R (U, F), where U = {A1, A2, A3 , A4, A5, A6}, dependent on a given function set F = A1 -> (A2, A3); A3-> A4 ; (A2, A3) -> (A5, A6); A6-> A1}, there is an exploded r = R1 (A1, A2, A3, A4), R2 (A3, A4, A5, A6)}, the Q break down__________.
A. having both destructive connectivity, while maintaining the functional dependency
B. connectivity does not have a non-destructive, but remains functional dependency
C. with lossless connectivity, but does not rely on holding function
D. connectivity has neither destructive nor maintained functional dependency
Answer: D
2. given relational schema R (U, F), where U = {A1, A2, A3 , A4, A5, A6}, dependent on a given function set F = A1 -> (A2, A3); A3 -> A4; (A2, A3 ) -> (A5, A6); A5-> A1}, there is an exploded r = R1 (A1, A2, A3, A4), R2 (A2, A3, A5, A6)} asked the decomposition __________.
A. having both destructive connectivity, while maintaining the functional dependency
B. connectivity does not have a non-destructive, but remains functional dependency
C. with lossless connectivity, but does not rely on holding function
D. connectivity has neither destructive nor maintained functional dependency
Answer: C
3. given relational schema R (U, F), where U = {A1, A2, A3 , A4, A5, A6}, dependent on a given function set F = A1 -> (A2, A3); A3 -> A4; (A2, A3 ) -> (A5, A6); A5-> A2}, there is an exploded r = R1 (A1, A2, A3, A4), R2 (A2, A3, A5, A6)} asked the decomposition __________.
A. having both destructive connectivity, while maintaining the functional dependency
B. connectivity does not have a non-destructive, but remains functional dependency
C. with lossless connectivity, but does not rely on holding function
D. connectivity has neither destructive nor maintained functional dependency
Answer: A
4. Given the relational schema R (U, F), where U = {A1, A2, A3 , A4, A5, A6}, dependent on a given function set F = A1 -> (A2, A3); A3 -> A4; (A2, A3 ) -> A5; A6-> A3}, there is an exploded r = R1 (A1, A2, A3, A4), R2 (A2, A3, A5, A6)}, the decomposition Q __________.
A. having both destructive connectivity, while maintaining the functional dependency
B. connectivity does not have a non-destructive, but remains functional dependency
C. with lossless connectivity, but does not rely on holding function
D. connectivity has neither destructive nor maintained functional dependency
Answer: B
5. The mode given relation R (U, F), where U = {A1, A2, A3 , A4, A5}, given functional dependency set F = A2-> A1; A4-> A1; A1- > A5; (A1, A3) -> A2;}. A decomposition r = {R1 (A1, A2 , A3, A5), R2 (A3, A4)}, the decomposition Q __________.
A. having both destructive connectivity, while maintaining the functional dependency
B. connectivity does not have a non-destructive, but remains functional dependency
C. with lossless connectivity, but does not rely on holding function
D. connectivity has neither destructive nor maintained functional dependency
The answer: D
