Explain the trade-offs between different database indexing strategies for a food-ordering system.
Use the supplied tables and query workload to produce the requested order totals, then explain which indexes would support this access pattern and their costs.
Output
- One row per completed order created in January 2026, excluding orders outside the date range or with another status.
- Columns:
order_id, restaurant_id, created_at, and order_total.
- Include completed orders with no items as
0.00. Order by created_at ascending, then order_id ascending.
