Java Companion

Apr 17, 2026 · Backend Development

Resolving ID Conflicts After Sharding: 5 Practical Solutions

When sharding databases, independent auto‑increment IDs can collide; this article explains why the conflict occurs and evaluates five concrete solutions—UUID, MySQL auto‑increment step, segment allocation, Snowflake algorithm, and Meituan Leaf—detailing their mechanisms, trade‑offs, performance, and suitability.