عرض عملي: اختيار مفتاح شريحة للطلبات

خطوة بخطوة

1. List the main queries: order by id, orders by customer, ops reports by date.
2. Analyze real order data for distribution by customer and by order id.
3. Planned mistake: choose order id hash because it spreads evenly. Fix: "my orders" now hits all shards; choose customer id with salting for large customers or keep a lookup table.
4. Quantify hot-partition risk using the top customers' share.
5. Outline resharding and the migration plan.
6. Record the decision in an ADR.