An evaluation of strict timestamp ordering concurrency control for main-memory database systems

Abstract

With the fundamental change of hardware technology, mainmemory database systems have emerged as the next generation of DBMS. Thus, new methods to execute transactions in a serial, lock-free mode have been investigated and successfully employed, for instance in H-Store or HyPer. Although these techniques allow for unprecedentedly high throughput for suitable workloads, their throughput quickly diminishes once unsuitable transactions, for instance those crossing partition borders, are encountered. Still, little research concentrates on the overdue re-evaluation of traditional techniques, that do not rely on partitioning. This paper studies strict timestamp ordering (STO), a “good old” technique, in the context of modern main-memory database systems built on commodity hardware with high memory capacities. We show that its traditional main drawback-slowing down reads-has a much lower impact in a main-memory setting than in traditional disk-based DBMS. As a result, STO is a competitive concurrency control method which outperforms the partitioned execution approach, for example in the TPC-C benchmark, as soon as a certain percentage of the workload crosses partition boundaries.