The log told the truth. The query did not.

When you debug logging access in Postgres through the binary protocol while proxying, every byte counts and every microsecond matters. Without deep visibility, the binary protocol feels opaque. Data moves over the wire as compact, high‑performance messages. Errors hide inside them. Latency hides inside them. The wrong proxy setup hides problems until they burn production.

To get this right, you need logging at the proxy level that does not just pipe text. You need full request/response introspection in the same structured way Postgres itself understands. That means enabling debug logging on the wire and capturing each message in the binary protocol before it hits the database and after it comes back.

The proxy becomes your X‑ray. Every Parse, Bind, Execute, Sync, and ErrorResponse can be recorded, timestamped, and linked to client connection IDs. You will see parameter binding in real time. You will see the difference between an idle connection and a slow query. You will see authentication messages unfold byte‑by‑byte.

Capturing this is simple if your proxy supports raw Postgres binary protocol inspection. The steps are:

1. Configure the proxy to accept and decode native Postgres messages instead of treating the stream as opaque TCP packets.
2. Enable structured logging output in JSON or another machine‑readable format for easier correlation in log aggregation tools.
3. Store both frontend‑to‑backend and backend‑to‑frontend traffic with exact timestamps.
4. Filter by message type to avoid overwhelming storage while still catching problem queries.

Common mistakes include logging only SQL text without parameters, dropping backend messages during high traffic, or assuming that SSL termination prevents logging. With the right setup, you can decode SSL‑wrapped traffic at the proxy and still log the binary protocol cleanly.

Performance still matters. High‑volume Postgres proxy logging should be asynchronous. Avoid log sinks that block query processing. Beware of disk I/O bottlenecks. On busy systems, high‑granularity binary protocol logging can produce gigabytes of data per hour. Use dynamic log level control to turn deep logging on only when you need it.

When implemented well, debug logging of Postgres binary protocol through a proxy becomes more than troubleshooting. It gives you traffic analytics, security auditing, and query performance insights in one stream. You no longer guess what the client sent. You know.

If you want to see full Postgres binary protocol proxy debug logging running live without building it yourself, try it now on hoop.dev. Spin it up in minutes. Capture every message. Find the truth in the log.