\begin{frame}
  \frametitle{First Normal Form}

  \begin{block}{}
    The \emph{First Normal Form (1NF)} requires that all \emph{table entries are atomic} 
    (\textit{not} lists, sets, records, relations).
  \end{block}  
  In the relational model all table entries are already atomic.

  \begin{goal}{}
    All further normal forms assume that tables are in 1NF!
  \end{goal}
  \bigskip\pause
  
  \begin{alertblock}{}
    The following are \emph{not violations of 1NF}:
    \begin{itemize}
      \item 
        a table entry contains values with internal structure
        \begin{itemize}
          \item e.g. a \sql{char(100)} containing a comma separated list 
        \end{itemize}
      \item 
        a list represented by several columns
        \begin{itemize}
          \item e.g. columns \sql{value1}, \sql{value2}, \sql{value3}
        \end{itemize}
    \end{itemize}
    Nevertheless, these are \emph{bad design}.
  \end{alertblock}
\end{frame}