Google Professional Cloud Database Engineer Exam - Topic 3 Question 25 Discussion

Actual exam question for Google's Professional Cloud Database Engineer exam

Question #: 25
Topic #: 3

[All Professional Cloud Database Engineer Questions]

You are the DBA of an online tutoring application that runs on a Cloud SQL for PostgreSQL database. You are testing the implementation of the cross-regional failover configuration. The database in region R1 fails over successfully to region R2, and the database becomes available for the application to process dat

a. During testing, certain scenarios of the application work as expected in region R2, but a few scenarios fail with database errors. The application-related database queries, when executed in isolation from Cloud SQL for PostgreSQL in region R2, work as expected. The application performs completely as expected when the database fails back to region R1. You need to identify the cause of the database errors in region R2. What should you do?

ADetermine whether the versions of Cloud SQL for PostgreSQL in regions R1 and R2 are different.

BDetermine whether the database patches of Cloud SQI for PostgreSQL in regions R1 and R2 are different.

CDetermine whether the failover of Cloud SQL for PostgreSQL from region R1 to region R2 is in progress or has completed successfully.

DDetermine whether Cloud SQL for PostgreSQL in region R2 is a near-real-time copy of region R1 but not an exact copy.

Show Suggested Answer

Suggested Answer: D

Verify that the replica has processed all the transactions it has received from the primary. This ensures that when promoted, the replica reflects all transactions that were received before the primary became unavailable. https://cloud.google.com/sql/docs/postgres/replication/cross-region-replicas#verify_failover_criteria

by Cyndy at Jan 27, 2024, 04:01 AM

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Lamar

3 months ago

I doubt it's the failover process; it should be smooth.

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France

3 months ago

Wait, are they not exact copies? That seems risky!

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Alease

4 months ago

I agree, the patches are often overlooked!

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Jenifer

4 months ago

I think it's definitely the database patches causing issues.

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Jacquelyne

4 months ago

Check the versions in R1 and R2 first. Could be a mismatch.

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Daron

4 months ago

I think the idea of R2 being a near-real-time copy is interesting. If it's not an exact copy, that could explain some discrepancies in the application behavior.

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Deane

4 months ago

I feel like the failover status could be a factor, but I can't recall if it would directly cause the errors we're seeing.

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Marylin

4 months ago

I'm not entirely sure, but I think checking the database patches might be important too. We had a practice question about patching that seemed relevant.

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Emmanuel

5 months ago

I remember we discussed version differences in our study group. If R1 and R2 have different versions, that could definitely cause issues.

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Carlton

5 months ago

I feel pretty confident about this one. I'd focus on checking the database versions and patches first, as that seems like the most likely culprit based on the information provided.

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Ligia

5 months ago

Okay, my strategy would be to first determine if the database in region R2 is an exact copy of the one in region R1. If it's not, that could explain why certain scenarios are failing.

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Cyndy

5 months ago

Hmm, I'm a bit confused here. Is the failover still in progress or has it completed successfully? That could be a key factor in understanding what's going on.

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Ammie

5 months ago

This seems like a tricky one. I'd start by checking if the database versions and patches are the same between the two regions. That could definitely cause issues if they're not aligned.

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Justine

5 months ago

For this type of question, I find it helpful to consider the key characteristics of each business environment. Mature and fragmented seems like the best fit based on the strategies mentioned.

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Leeann

5 months ago

Hmm, I'm not too sure about this one. I'll have to think it through carefully. Maybe the peer-to-peer option could work, but I'm not confident.

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Maxima

5 months ago

I'm a bit confused by the wording of the question. Does "choose two" mean we have to select exactly two options, or can we choose just one if we think that's the best solution? I want to make sure I understand the requirements before answering.

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Aleta

2 years ago

Hmm, I wonder if the database in region R2 is secretly running a version of PostgreSQL that's been heavily modified by the Cloud SQL team, with some hidden features that are causing issues. Or maybe they just forgot to add the 'magical unicorn dust' that keeps the database happy in region R2. *chuckles*

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Katina

2 years ago

D) Determine whether Cloud SQL for PostgreSQL in region R2 is a near-real-time copy of region R1 but not an exact copy.

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Francisca

2 years ago

C) Determine whether the failover of Cloud SQL for PostgreSQL from region R1 to region R2 is in progress or has completed successfully.

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Yuki

2 years ago

A) Determine whether the versions of Cloud SQL for PostgreSQL in regions R1 and R2 are different.

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Evangelina

2 years ago

B) Determine whether the database patches of Cloud SQL for PostgreSQL in regions R1 and R2 are different.

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Yvonne

2 years ago

A) Determine whether the versions of Cloud SQL for PostgreSQL in regions R1 and R2 are different.

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Lajuana

2 years ago

You know, I was leaning towards option B at first, thinking there might be some database patches missing in region R2. But the fact that the application-related queries work in isolation makes me doubt that's the issue. I'm with you guys on option D - it just makes the most sense given the information provided.

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Quentin

2 years ago

I agree, option D does seem the most plausible explanation. The fact that the application works as expected when the database fails back to region R1 suggests that the issue is specific to the database in region R2. It could be that the replication process is not keeping the databases in perfect sync, leading to some inconsistencies.

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Timothy

2 years ago

Hmm, this question seems to be testing our understanding of the cross-regional failover process and potential issues that might arise. I'm thinking option D might be the most likely culprit here. If the database in region R2 is not an exact copy of the one in region R1, it could explain why certain scenarios are failing, even though the queries work in isolation.

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