Tutorial By Namitha

Dependency Preserving Decomposition  If we decompose a relation R into relations R1 and R2, All dependencies of R either must be a part of R1 or R2 or must be derivable from   FD’s of R1 and R2 .    Relation R is decomposed in to R1 and R2 with FDs F1 and F2 respectively  ,  if the decomposition is dependency preserving then F1 U F2 =F                                                and so           ( F1 U F2 ) + =F+