Exam Professional Data Engineer All Questions

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Exam Professional Data Engineer topic 1 question 211 discussion

Actual exam question from Google's Professional Data Engineer

Question #: 211
Topic #: 1

[All Professional Data Engineer Questions]

You are using BigQuery with a multi-region dataset that includes a table with the daily sales volumes. This table is updated multiple times per day. You need to protect your sales table in case of regional failures with a recovery point objective (RPO) of less than 24 hours, while keeping costs to a minimum. What should you do?

A. Schedule a daily export of the table to a Cloud Storage dual or multi-region bucket.
B. Schedule a daily copy of the dataset to a backup region.
C. Schedule a daily BigQuery snapshot of the table.
D. Modify ETL job to load the data into both the current and another backup region.

Show Suggested Answer

Suggested Answer: A 🗳️

by e70ea9e at Dec. 30, 2023, 9:34 a.m.

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MaxNRG

Highly Voted 1 year, 6 months ago

Selected Answer: A

Why not C: A table snapshot must be in the same region, and under the same organization, as its base table. https://cloud.google.com/bigquery/docs/table-snapshots-intro#limitations

upvoted 15 times

MaxNRG

1 year, 6 months ago

Based on the information provided and the need to avoid data loss in the case of a hard regional failure in BigQuery, which could result in the destruction of all data in that region, the focus should be on creating backups in a geographically distinct region. Considering this scenario, the most suitable option would be Option A Here's why this option is the most appropriate:

upvoted 5 times

MaxNRG

1 year, 6 months ago

• Cross-Region Backup: Exporting the data to a Google Cloud Storage bucket that is either dual or multi-regional ensures that your backups are stored in a different geographic location. This is critical for protecting against hard regional failures. • Data Durability: Cloud Storage provides high durability for stored data, making it a reliable option for backups in the case of regional disasters. • Cost-Effectiveness: While there are costs associated with storage and data transfer, this method can be more cost-effective compared to maintaining active replicas of the data in multiple regions, especially if the data is large.

upvoted 3 times

MaxNRG

1 year, 6 months ago

• Flexibility and Automation: The export process can be automated and scheduled to occur daily, aligning with your RPO of less than 24 hours. This ensures that the most recent data is always backed up. • Recovery Process: In the event of a hard regional failure, the data can be restored from the Cloud Storage backup to another operational BigQuery region, ensuring continuity of operations.

upvoted 3 times

MaxNRG

1 year, 6 months ago

The other options, while viable in certain scenarios, do not provide the same level of protection against a hard regional failure: • Option B (Copy to Backup Region) and Option D (Modify ETL to Load into Backup Region) do not address the possibility of a hard regional failure adequately, as they do not necessarily imply storing data in a geographically distinct region. • Option C (BigQuery Snapshot) is useful for point-in-time recovery but does not inherently protect against hard regional failures since the snapshots are within the same BigQuery service. Focusing on a robust disaster recovery strategy is crucial. Option A provides a balance between ensuring data availability in the event of a regional disaster and managing costs, aligning with best practices for data management in the cloud.

upvoted 4 times

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raaad

Highly Voted 1 year, 7 months ago

Selected Answer: C

Option C provides cost-effective way. - BigQuery table snapshots are a feature that allows you to capture the state of a table at a particular point in time. - Snapshots are incremental, so they only store the data that has changed, making them more cost-effective than full table copies. - In the event of a regional failure, you can quickly restore the table from a snapshot.

upvoted 7 times

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ToiToi

Most Recent 9 months ago

Selected Answer: A

Why other options are not as suitable: B (Copy of the dataset): Copying the entire dataset daily is more expensive and less efficient than exporting just the table data. C (BigQuery snapshot): snapshots are within the same region and won't protect against a regional outage. D (Modify ETL job): This adds complexity to your ETL process and might not be the most efficient or cost-effective way to achieve your RPO.

upvoted 2 times

desertlotus1211

4 months, 1 week ago

What about the cost inplications? BigQuery exports are full-table exports, so you pay for every row scanned and written. Storage in multi-region buckets is a bit more expensive than single-region. Answer C is better suited

upvoted 1 times

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Priyal19

11 months, 1 week ago

A : BQ snapshot should be in same region, and if so the region fails so does the snapshot.

upvoted 1 times

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viciousjpjp

11 months, 2 weeks ago

Selected Answer: C

Why Option A is not suitable: Restoring data from Option A would require reloading it back into BigQuery, which is time-consuming. This process cannot guarantee a recovery point objective (RPO) of less than 24 hours.

upvoted 2 times

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1 year, 5 months ago

Selected Answer: C

C. Schedule a daily BigQuery snapshot of the table. Here's why: Cost-effective: BigQuery snapshots are significantly cheaper than daily exports to Cloud Storage or copying the entire dataset to a backup region. They offer point-in-time backups with minimal storage costs. Fast recovery: Snapshots can be restored quickly, meeting your RPO requirement of less than 24 hours. Multi-regional: By default, BigQuery snapshots are automatically stored in a different region from the source data, ensuring redundancy and disaster recovery.

upvoted 2 times

1 year, 6 months ago

Selected Answer: A

"BigQuery does not offer durability or availability in the extraordinarily unlikely and unprecedented event of physical region loss. This is true for both "regions and multi-region" configurations. Hence maintaining durability and availability under such a scenario requires customer planning." "To avoid data loss in the face of destructive regional loss, you need to back up data to another geographic location. For example, you could periodically export a snapshot of your data to Google Cloud Storage in another geographically distinct region." Ref: https://cloud.google.com/bigquery/docs/reliability-intro#scenario_loss_of_region

upvoted 5 times