On-Line Transaction Processing (OLTP) systems constitute the kernel of the information systems used today to support the daily operations of most organizations. Although these systems comprise the best examples of complex business-critical systems, no practical way has been proposed so far to characterize the impact of faults in such systems or to compare alternative solutions concerning dependability features. This paper presents a practical example of benchmarking key dependability features of four different transactional systems using a first proposal of dependability benchmark for OLTP application environments. This dependability benchmark is an extension to the TPC-C standard performance benchmark, and specifies the measures and all the steps required to evaluate both the performance and dependability features of OLTP systems. Two different versions of the Oracle transactional engine running over two different operating systems were evaluated and compared. The results show that dependability benchmarking can be successfully applied to OLTP application environments.