F={AB->C,A->DE,B->F,F->GH,D->IJ}
D1={DIJ,ACE,FGH,BF,ADC}
CANDIDATE KEY FOR 1ST RELATION IS (AB)
THERE IS COMMON ATTRIBUTE OF (AB) FOR ALL DECOMPOSITION RELATIONS
SO IT IS LOSSY JOIN
dependencies correspanding D1 realtions are
D->IJ,A->E,AC->E,F->GH,B->F,A->D
check D1 covers F are not?
(AB)+ is not derive C
so not dependecy preservation
@)D2={FGH,DIJ,ADEBF,ABC)
IT IS LOSSLESS JOIN DEPENDENCY
dependencies are
D2={F->GH,D->IJ,AB->D,AB->E,AB->F,B->F,A->DE,A->BC}
it satisfies F covers D2 and D2 covers F
so it is dependency preserving.
3)R(ABCDEG)
F={AB->C,AC->B,AD->E,B->D,BC->A,E->G}
it is lossless join dependency.
D3={AB->C,BC->A,AC->B,AC->D,AC->E,AD->E,AD->G}
check Fcovers D3 are not?
D3 NOT COVERS F because (E)+ not derive G
so not dependecy preservation