Buffer Pool Management, Page Replacement Policies, and Modern Asynchronous I/O: Pin Counts, Scan Resistance (LRU-K, 2Q, Clock-Sweep), Pointer Swizzling, and Linux iouring

Deep End Era. Engineering with Sankalp · Oct 29, 2026 · 1h 5m

Every time an analytical background report runs against your primary database, latency on your hot checkout transactions mysteriously spikes by fiftyfold. To understand why—and how modern storage engines stop it—we open up the architecture of the Database Buffer Pool: Wolfgang Effelsberg and Theo Härder's 1984 buffer management principles; Andrew Pavlo's 2022 warning on why mmap and OS page caches sabotage transactional correctness and performance; pin counts, reader-writer page latches versus transactional row locks, and page hash table partitioning; scan-resistant eviction algorithms from…