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\begin{frame}
\frametitle{Introduction}

\begin{goal}{}
There are different normal forms. The main ones are:
\medskip
\begin{itemize}
\item \emph{Third Normal Form (3NF)}:
the standard relational normal form
used in practice (and education).
\medskip
\item \emph{Boyce-Codd Normal Form (BCNF)}:
\begin{itemize}
\item a bit more restrictive
\item easier to define
\item better for our intuition of good database design
\end{itemize}
Roughly speaking, BNCF requires that \emph{all FDs are keys.}
\end{itemize}
\end{goal}
\medskip

In rare circumstances, a relation might not have an equivalent
BCNF form while preserving all its FDs.\\
\remark{The 3NF normal form always exists (and preserves the FDs).}
\end{frame}