\begin{frame}
  \frametitle{Concurrent Access \& Transactions}
  
  \begin{goal}{Motivation for database management systems}
    \begin{itemize}
      \item multiple users, \emph{concurrent access}
        \begin{itemize}
          \item transactions with ACID properties
        \end{itemize}
    \end{itemize}
  \end{goal}

  \begin{block}{}
    A \emph{transaction} is a sequence of operations that
    performs a single logical function in a database application.
  \end{block}
    
  \begin{block}{Database management system ensures \emph{ACID properties}}
    \begin{itemize}
      \item \emph{Atomicity:} transaction executes fully (commit) or not at all (abort)
      \item \emph{Consistency:} database remains in a consistent state where all 
        integrity constraints hold
      \item \emph{Isolation:} multiple users can modify the database at the same time
        but will not see each others partial actions
      \item \emph{Durability:} once a transaction is committed successfully,
        the modified data is persistent, regardless of disk crashes
    \end{itemize}
  \end{block}
  
\end{frame}