OLTP Benchmark is used to evaluate the performance and cost of transactional database systems. It supports various OLTP workloads and allows evolving mixtures of transactions over time. The benchmark was used to compare the performance per dollar of different Amazon RDS instance sizes for YCSB and Wikipedia workloads. For YCSB, the L instance provided the best cost-performance ratio, while the XL-HM instance was best for Wikipedia. OLTP Benchmark can also smoothly change the transaction mixture during a run to evaluate how systems respond. It provides a standardized way to test OLTP databases and compare cloud database offerings.