Question 130
For Mercury Travel Tech, the engineer must verify a remediation with measured evidence, not just a deployment claim. The original failure was: A small exploratory tabular dataset is routed through a complex distributed cluster that takes longer to initialize than the analysis itself. Which independently observable result best verifies that the remediation works?
Explanation
Correct Answer
The notebook processes the complete sample within memory limits and reproduces the same cleaned output without cluster startup overhead. This controlled observation specifically validates the proposed remedy: Use in-memory Python preprocessing for the bounded dataset while recording inputs and transform versions for reproducibility. It addresses the documented failure at Mercury Travel Tech: A small exploratory tabular dataset is routed through a complex distributed cluster that takes longer to initialize than the analysis itself.
Incorrect Answers
Injected out-of-order events reach the correct windows without duplicate feature records under replay. This is evidence for a different corrective change: Build an event-time-aware streaming pipeline using Dataflow with watermarks, lateness handling, and idempotent writes. That other change addresses: A mobile events platform receives late, out-of-order user events but runs a daily file-only ETL that misses required real-time features. It does not validate the specific Mercury Travel Tech remediation for: A small exploratory tabular dataset is routed through a complex distributed cluster that takes longer to initialize than the analysis itself. The necessary check instead is: The notebook processes the complete sample within memory limits and reproduces the same cleaned output without cluster startup overhead.
Historical replay retrieves status as it was at each event time, rather than the latest account record. This is evidence for a different corrective change: Use event-time or point-in-time feature retrieval against effective-dated feature values. That other change addresses: A recommendation model joins current customer status to old events, creating implausible historical feature values from updated records. It does not validate the specific Mercury Travel Tech remediation for: A small exploratory tabular dataset is routed through a complex distributed cluster that takes longer to initialize than the analysis itself. The necessary check instead is: The notebook processes the complete sample within memory limits and reproduces the same cleaned output without cluster startup overhead.
A batch loader retrieves images by reference with valid labels and no redundant large inline binary columns. This is evidence for a different corrective change: Keep image objects in Cloud Storage and maintain governed labels and object references in a queryable catalog. That other change addresses: An image classification team stores training images directly in BigQuery rows as base64 strings, making batch loading inefficient and costly. It does not validate the specific Mercury Travel Tech remediation for: A small exploratory tabular dataset is routed through a complex distributed cluster that takes longer to initialize than the analysis itself. The necessary check instead is: The notebook processes the complete sample within memory limits and reproduces the same cleaned output without cluster startup overhead.