Publishers send package-tracking messages to one Pub/Sub topic; a subscriber processes them and writes to BigQuery for historical analysis. To ensure events can be analyzed over time, what should you include and where?

Attaching the timestamp and Package ID at the source (publisher device) ensures the most accurate record of when the event occurred and provides a unique identifier for each package. This is crucial for historical analysis, as it captures the true event time, independent of network latency or processing delays. Incorrect options: Attaching the timestamp in the subscriber application introduces latency, meaning the recorded time would reflect when the message was processed, not when the event happened. Using NOW() in BigQuery would record the time the data was loaded into BigQuery, which is even further removed from the actual event time and inconsistent. While Cloud Pub/Sub automatically generates a publishtime timestamp, it reflects when Pub/Sub received the message, not when the event originated. For precise historical analysis, the original event timestamp is preferred.