How to recover from BigQuery table corruption within 7 days with lowest RPO?

PDE By islever Editorial Last updated

Short answer

A Access historical data by using time travel in BigQuery.

Question

You are designing a fault-tolerant architecture to store data in a regional BigQuery dataset. You need to ensure that your application is able to recover from a corruption event in your tables that occurred within the past seven days. You want to adopt managed services with the lowest RPO and most cost-effective solution. What should you do?
  1. Access historical data by using time travel in BigQuery. Correct Answer
  2. Export the data from BigQuery into a new table that excludes the corrupted data
  3. Create a BigQuery table snapshot on a daily basis.
  4. Migrate your data to multi-region BigQuery buckets.

Key Takeaways

The question tests understanding of BigQuery's time travel and snapshots for disaster recovery, with the trap being that daily snapshots seem reliable but have a 24-hour RPO and extra costs.

Time travel in BigQuery provides built-in point-in-time recovery for up to seven days, offering the lowest RPO at no extra cost, making it the best choice for recovering from table corruption. Community experts agree that daily snapshots are less optimal due to a higher RPO and additional storage costs.

Common mistake: Option C (daily table snapshots) is the most likely wrong choice because it appears to be a managed backup solution, but it introduces up to 24 hours of data loss and ongoing storage costs, whereas time travel provides immediate recovery with zero extra cost.

Expert Analysis

Why the Answer Is Correct

Option A, using BigQuery time travel, is the best answer because it offers point-in-time recovery for any moment within the past seven days, giving the lowest possible RPO (seconds to minutes) with no additional storage or operational costs. BigQuery time travel is a fully managed built-in feature, so no separate backup infrastructure is required. The top comment (15 likes) explains that time travel provides 'the shortest possible recovery point objective' and incurs 'no additional costs', directly matching the question's requirements.

Why the Other Options Are Wrong

Option B (exporting data to a new table) is a manual and error-prone process that cannot precisely restore the pre-corruption state; it also relies on having an earlier backup or external copy. Option C (daily table snapshots) does provide a managed recovery mechanism, but as a commenter notes, the RPO is 'at most 24 hours', which is higher than time travel's granular recovery, and snapshots involve storage costs. Option D (migrating to multi-region BigQuery buckets) is unrelated to table-level corruption recovery and does not help restore individual tables.

Community Comment Notes

The top voted comment (15 likes) strongly supports A, highlighting time travel's zero cost and lowest RPO. A dissenting comment (1 like) argued for C, but its own reasoning admits daily snapshots have an RPO of up to 24 hours—this actually reinforces why C is inferior. Multiple additional comments simply vote for A. The consensus is clear: time travel is the correct, cost-effective managed solution for recovering within the seven-day retention window.

Official Reference

These links open the official vendor documentation in a new tab.

Exam Strategy

When a question asks for the lowest RPO and most cost-effective managed solution, check if the data is within the seven-day time travel window. Remember that BigQuery time travel is free and provides second-level granularity, while table snapshots are better for longer retention but cost extra and have a higher RPO.

Community Votes

A
100%

100% of anonymous learners picked answer A. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 6 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 6

  1. raaad 👍 15 Answered A
    - Lowest RPO: Time travel offers point-in-time recovery for the past seven days by default, providing the shortest possible recovery point objective (RPO) among the given options. You can recover data to any state within that window. - No Additional Costs: Time travel is a built-in feature of BigQuery, incurring no extra storage or operational costs. - Managed Service: BigQuery handles time travel automatically, eliminating manual backup and restore processes.
  2. Matt_108 👍 3 Answered A
    Option A, raaad explanation is perfect
  3. CGS22 👍 1 Answered C
    Meets Recovery Needs: Table snapshots provide point-in-time copies of your data, allowing you to restore data from any point within the last seven days, effectively addressing the corruption event recovery requirement. Low RPO: With daily snapshots, your Recovery Point Objective (RPO) is at most 24 hours, satisfying the need for a low RPO. Managed Service: Table snapshots are a fully managed service within BigQuery, aligning with your preference. Cost-Effective: Snapshots only store the changes from the base table, minimizing storage costs compared to full table copies.
  4. scaenruy 👍 1 Answered A
    A. Access historical data by using time travel in BigQuery.
  5. hanoverquay 👍 1 Answered A
    vote for A
Show 1 more comment
  1. JyoGCP 👍 1 Answered A
    Option A

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