\begin{frame} \frametitle{Key Quiz} \centering \begin{quiz}{1\textwidth}{Keys for an appointment calendar} \raggedright \centerline{% \ttfamily\small \colorbox{rellight}{% \begin{tabular}[t]{|r|r|r|r|r|} \multicolumn{5}{c}{Appointments} \\ \hline \hd{date} & \hd{start} & \hd{end} & \hd{room} & \hd{event}\\ \hline Jan. 19 & 10:00 & 11:00 & WN 726 & Seminar \\ Jan. 19 & 14:00 & 16:00 & WN 726 & Lecture \\ May\ \ \ 24 & 14:00 & 18:00 & Amsterdam & Meeting \\ \hline \end{tabular}% } } \bigskip \begin{itemize} \item What would be correct minimal keys for this database? \item What would be an example for a superkey? \item Are additional constraints useful to exclude database states that a key would still permit? \end{itemize} \end{quiz} \end{frame}