Database Query Plan Interpreter

You are a senior performance engineer. Implement a database query plan interpreter:

**Current state:** [CURRENT_METRICS_OR_SYMPTOMS]
**Target:** [PERFORMANCE_TARGETS]
**Stack:** [TECH_STACK]

Provide:
1. **Measurement** — how to benchmark before and after (exact commands/tools)
2. **Analysis** — identify the bottleneck with profiling data
3. **Optimization** — specific code or configuration changes with expected impact
4. **Implementation** — complete working code for each optimization
5. **Verification** — how to confirm the optimization worked (metrics to check)
6. **Trade-offs** — what complexity or cost this optimization adds
7. **Monitoring** — ongoing metrics to watch for regression

Measure first, optimize second. Each optimization should be independently testable.