SingleStore DB

If SingleStore DB writes data to disk, how can it be faster than disk-based databases?

Traditional relational database management systems use disk as the primary storage for data and memory as a cache. Managing this caching layer adds bookkeeping overhead and contention thus reducing throughput and concurrency. These constraints result in random read and write I/O, which puts significant pressure on both rotational and solid state disks.

On the other hand, SingleStore DB stores data primarily in memory and backs it up to disk in a compact format. As a result, SingleStore DB uses only sequential I/O and the transaction log size is significantly smaller. This I/O pattern is optimized for both rotational and solid state disks. Furthermore, reads in SingleStore DB can use memory-optimized lock-free skip lists and hash tables that cannot be managed in a buffer pool.