\begin{frame}
  \frametitle{Simple Aggregations}

  \structureAll
  
  \begin{code}{\textwidth}{How many Students have submitted a homework?}
    \pause
    {
      \small
      \BUseVerbatim{howmany}
    }

    \begin{center}
      \colorbox{rellight}{%
        \footnotesize\centering\ttfamily
        \begin{tabular}{|r|}
          \hline
          \hd{count(distinct sid)} 
          \\
          3
          \\
          \hline
        \end{tabular}%
      }
    \end{center}
  \end{code}
  \pause\vspace{-1.75ex}
  
  \begin{code}{\textwidth}{What is the total number of points student 101 got for her homeworks?}
    \pause
    {
      \small
      \BUseVerbatim{total}
    }
    \begin{center}
      \colorbox{rellight}{%
        \footnotesize\centering\ttfamily
        \begin{tabular}{|r|}
          \hline
          \hd{total points} 
          \\
          18
          \\
          \hline
        \end{tabular}%
      }
    \end{center}
  \end{code}
\end{frame}