\begin{frame} \frametitle{Transactions} Formally, transactions are defined as: \begin{goal}{} A \emph{transaction} is a list of actions. \medskip The \emph{actions} are \begin{itemize} \item reads (written \tread{O}) and \item writes (written \twrite{O}) \end{itemize} of database objects O. \medskip Transactions end with \emph{Commit} or \emph{Abort}.\\ \remark{% These are sometimes omitted if not relevant. } \end{goal} \medskip \begin{exampleblock}{Example Transaction} \begin{malign} T_1 \;:\; \tread{V}, \tread{Y}, \twrite{V}, \twrite{C}, \tcommit \end{malign} \end{exampleblock} \end{frame}