173/296
\begin{frame}
  \frametitle{Splitting Relations}
  
  \begin{alertblock}{}
    It is important that this splitting transformation is
    \emph{lossless}, i.e., that the original relation can be
    reconstructed by a join.
  \end{alertblock}
  \pause
    
  \begin{exampleblock}{Reconstruction after split}
    \recallexamplephone
    \bigskip
    
    We can reconstruct the original table as follows:\smallskip
    
    $
    \begin{array}{r@{~~}l}
      \sql{CREATE} & \sql{VIEW COURSES (CRN, TITLE, INAME, PHONE)} \\
      \sql{AS} \\
      \sql{SELECT} & \sql{I.CRN, I.TITLE, I.INAME, P.PHONE} \\
      \sql{FROM}   & \sql{INTSTRUCTORS I, PHONEBOOK P}      \\
      \sql{WHERE}  & \sql{I.INAME = P.INAME} 
    \end{array}
    $
  \end{exampleblock}
\end{frame}