Database Engines on Multicores, Why Parallelize When You Can Distribute?

摘要

Multicore computers pose a substantial challenge to infrastructure software such as operating systems or databases. Such software typically evolves slower than the underlying hardware, and with multicore it faces structural limitations that can be solved only with radical architectural changes. In this paper we argue that, as has been suggested for operating systems, databases could treat multicore architectures as a distributed system rather than trying to hide the parallel nature of the hardware. We first analyze the limitations of database engines when running on multicores using MySQL and PostgreSQL as examples. We then show how to deploy several replicated engines within a single multicore machine to achieve better scalability and stability than a single database engine operating on all cores. The resulting system offers a low overhead alternative to having to redesign the database engine while providing significant performance gains for an important class of workloads.