Imagine you’re halfway through an online purchase and the power goes out. When the system restarts, your money should still be safe and your order either complete or not started at all. Database recovery strategies are the behind‑the‑scenes system that make this possible: after any failure — a crash, a power outage, or a disk error — they restore the database to a correct, consistent state without losing any committed work. In this chapter, we’ll explore how transaction logs, checkpoints, and a few clever algorithms make that happen.