When your database says “COMMIT successful,” it’s trusting a chain of hardware guarantees — and that hardware lies. RAM loses everything the moment power cuts. NAND flash, the storage inside every SSD, holds data by trapping electrons in a cage, and those electrons slowly leak. A cold SSD sitting unplugged in a warm room for a year can lose data silently, with no error, no warning, and no indication anything went wrong. Hard drives store bits as magnetic orientations on spinning metal platters. A strong enough nearby magnet flips them.

Databases don’t trust the hardware they sit on. The write-ahead log, the buffer pool, the fsync-before-commit sequence — all of it exists because engineers who built the first serious databases understood that hardware fails, stalls, and occasionally lies in ways that look exactly like success. You can’t understand why any of this machinery exists until you understand the physical constraints it’s working around. That’s the entire point of this first issue.