self doubt

Question

Is decomposition to BCNF ALWAYS POSSIBLE ??

can we decompose a relation to BCNF ALWAYS OR ARE THERE RELATIONS WHICH CANNOT BE DECOMPOSED TO BCNF ?

Answer 1

no decomposition to BCNF ALWAYS not POSSIBLE.

every relation possible to decompose into 1NF,2NF,3NF,BCNF with loss-less decomposition.

every relation possible to decompose into 1NF,2NF,3NF with dependency preserving but not every can decompose into BCNF with dependency preserving.

ex:

R(A B C)     F={ AB->C, C->A }

RELATION R NOT POSSIBLE TO decompose into BCNF with dependency preserving.