Build a request timeline from query history ​

Start a request investigation with the query ID rather than attempting to reconstruct activity from unrelated log lines. HTTP responses expose X-Coordinator-Query-Id; structured request history uses the same identifier.

SELECT event_time_text, type, query_duration_ms,
       read_rows, written_rows, exception_code
FROM system.query_log
WHERE query_id = 'replace-with-query-id'
ORDER BY event_time;

Record these events in time order when explaining a request to another reader. With logging enabled and a zero duration threshold, history records a start and terminal event. A nonzero threshold records only qualifying terminal events, so a missing start is not itself evidence of lost data.

For work still running, capture system.processes separately. It is a current snapshot, while query history describes recorded events. The current request's terminal event becomes available after execution completes.

These tables provide request measurements, not a distributed tracing export or stack-sampling interface. Keep a chart labeled with the observed event types and timestamp source rather than drawing unsupported spans. Include the exact SQL and relevant limits, with sensitive values removed.

See query history, active requests and HTTP metadata.