Suppose R is a relation schema and F is a set of functional dependencies on R. Further, suppose R1and R2 form a decomposition of R. Then the decomposition is a lossless join decomposition of R provided that:
A. R1∩R2→R1 is in F+
B. R1∩R2→R2 is in F+
C. both R1∩R2→R1 and R1∩R2→R2 functional dependencies are in F+
D. at least one from R1∩R2→R1 and R1∩R2→R2 is in F+
Answer:D
Suppose R is a relation schema and F is a set of functional dependencies on R. Further, suppose R1and R2 form a decomposition of R. Then the decomposition is a lossless join decomposition of R provided that:
A. R1∩R2→R1 is in F+ B. R1∩R2→R2 is in F+ C. both R1∩R2→R1 and R1∩R2→R2 functional dependencies are in F+ D. at least one from R1∩R2→R1 and R1∩R2→R2 is in F+