Prof. Dr. Tilmann Rabl


PMem vs. NVMe Database Performance Paper accepted at DaMoN '21

Our Paper "Drop It In Like It's Hot: An Analysis of Persistent Memory as a Drop-in Replacement for NVMe SSDs" by Maximilian Böther, Otto Kißig, Lawrence Benson, Tilmann Rabl was accepted at DaMoN 2021!

This paper is a direct result of our Data Management on Modern Storage Technologies master's course. Great work by Maximilian and Otto. Congratulations! Check our the code on GitHub.


Solid-state drives (SSDs) have improved database system performance significantly due to the higher bandwidth that they provide over traditional hard disk drives. Persistent memory (PMem) is a new storage technology that offers DRAM-like speed at SSD-like capacity. Due to its byte-addressability, research has mainly treated PMem as a replacement of or an addition to DRAM, e.g., by proposing highly-optimized, DRAM-PMem-hybrid data structures and system designs. However, PMem can also be used via a regular file system interface and standard Linux I/O operations. In this paper, we analyze PMem as a drop-in replacement for Non-Volatile Memory Express (NVMe) SSDs and show possible performance gains while requiring no or only minor changes to existing applications. To this end, we systematically evaluate PMem and NVMe SSDs in three database microbenchmarks and the widely used TPC-H benchmark on Postgres. Our experiments show that PMem outperforms a RAID of four NVMe SSDs in read-intensive OLAP workloads by up to 4x without any modifications while achieving similar performance in write-intensive workloads. Finally, we give four practical insights to aid decision-making on when to use PMem as an SSD drop-in replacement and how to optimize for it.