Patterns for Postgres Traffic Control — PlanetScale

PlanetScale's Database Traffic Control lets you attach resource budgets to slices of Postgres traffic using SQLCommenter tags. This post walks through practical Go patterns for implementing it: per-service isolation via Postgres roles, HTTP middleware for route-level tagging, feature flag tagging for safe deployments, tier-based limits in multi-tenant SaaS apps, and dedicated connection pools for background jobs. It also covers handling blocked queries (SQLSTATE 53000) with graceful degradation and retry logic, and observing Warn mode notices before switching to Enforce. The patterns compose together, letting you build layered traffic policies without complex rule logic.