\begin{frame}
  \frametitle{Example Database (Results)}
  
  \vspace{-1ex}
  \structureStudentsExercises
  
  \vspace{-1ex}
  \begin{exampleblock}{}
    {\ttfamily
    \begin{center}
      \tableResultsShort
    \end{center}}
    
    Meaning of the columns:
      \begin{description}\setlength{\itemindent}{0.1cm}
      \item [\sql{sid}:] identifies the student 
        (\hint{references \sql{Students}})
      \item [\sql{category}, \sql{number}:] identifies exercise 
         (\hint{references \sql{Exercises}})
      \item [\sql{points}:] graded points
      \end{description}
  \end{exampleblock}
\end{frame}