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\begin{frame}
  \frametitle{Schedules}

  \begin{goal}{}
    A \emph{schedule} is a list of actions from a \emph{set of transactions}.
  \end{goal}
  Intuitively, this is a plan on how to execute transactions.
  \smallskip\pause
    
  \begin{goal}{}
    The \emph{order} in which $2$ actions of a transaction $T$ 
    appear in a schedule must be the same order as they appear in $T$.
  \end{goal}
  \pause
    %   \begin{itemize}
    %     \item We usually write schedules from left to right.\\
    %       (sometimes from top to bottom)
    %   \end{itemize}
  
  \begin{exampleblock}{}
    \begin{malign}
      T_1 &\;:\; \tread{V} \; \twrite{V} \\
      T_2 &\;:\; \tread{Y} \; \twrite{Y}
    \end{malign}
    \smallskip
    
    Which of the following is a schedule of these transactions?
    \begin{center}
      \begin{tikzpicture}
        \schedule{$S_1$}{2}{1rV|2rY|2wY|1wV}
        \begin{scope}[yshift=-1.5cm]
        \schedule{$S_2$}{2}{1wV|2rY|2wY|1rV}
        \end{scope}
      \end{tikzpicture}
    \end{center}
  \end{exampleblock}
\end{frame}