Query Tracing Skill

Use distributed tracing (OpenTelemetry / Tempo) to understand where time is spent during SQL statement execution in a local Materialize instance.

For background on Materialize's tracing infrastructure (span levels, filtering, #[tracing::instrument], distributed context propagation), see doc/developer/tracing.md.

Important: Use Optimized Builds

Always trace --optimized builds. Debug builds introduce significant artifacts — unoptimized code, extra debug checks, and inflated self-times that don't reflect production behavior. Tracing a debug build can be misleading because time may appear in places that are negligible in release builds.

bin/environmentd --optimized --monitoring