\begin{frame} \frametitle{Data Independence} \begin{goal}{Logical data independence} \emph{Logical data independence} is the ability to modify the logical schema without breaking existing applications \begin{itemize} \item applications access the views, not the logical database \end{itemize} \end{goal} \medskip \begin{goal}{Physical data independence} \emph{Physical data independence} is the ability to modify the physical schema without changing the logical schema \begin{itemize} \item e.g. a change in workload might cause the need for \begin{itemize} \item different indexing structures \item different database engine \item distributing the database on multiple machines \item \ldots \end{itemize} \end{itemize} \end{goal} \end{frame}