\begin{frame}
  \frametitle{Aggregations}
  
  \begin{goal}{}
    \emph{Aggregation functions} are functions from a set or multiset to a
    single value, e.g.,
    \begin{talign}
    \min\,\{\, 42, 57, 5,13, 27 \,\} = 5
    \end{talign}
    They take as input the values of an entire column.
  \end{goal}
  \pause\medskip

  Aggregation functions are also known as
  \begin{itemize}
    \item \emph{group functions}, or
    \item \emph{column functions}
  \end{itemize}
  \medskip
  
  \begin{goal}{}
     Typical use: statistics, data analysis, report generation.
  \end{goal}
\end{frame}