Desirable Properties of Decomposition

1. We'll take another look at the schema

    Lending-schema = (bname, assets, bcity, loan#, cname, amount)
   
   

   which we saw was a bad design.

2. The set of functional dependencies we required to hold on this schema was:

    bname    assets bcity
   
   		 loan#    amount bname
   
   

3. If we decompose it into

    Branch-schema = (bname, assets, bcity)
   
   		 Loan-info-schema = (bname, loan#, amount)
   
   		 Borrow-schema = (cname, loan#)
   
   

   we claim this decomposition has several desirable properties.

• Lossless-Join Decomposition
• Dependency Preservation
• Repetition of Information