Exam Professional Cloud Developer topic 1 question 19 discussion

As mentioned here https://cloud.google.com/spanner/docs/reference/rest/v1/TransactionOptions read-write transaction type has no options, and there is no way to make stale reads with this transaction type, so D) is definitely wrong. In the question, low latency is more critical than consistency, so C) is not an option. Read-Only transactions can do stale reads as well as Single Read methods, but in the documentation https://cloud.google.com/spanner/docs/transactions#read-only_transactions , they encourage to use SingleRead methods where possible. My vote is B)

https://cloud.google.com/spanner/docs/reads: "A stale read is read at a timestamp in the past. If your application is latency sensitive but tolerant of stale data, then stale reads can provide performance benefits." B is the answer since the qn is asking about reading from Cloud Spanner; no writes involved

B. Perform stale reads using single-read methods: Stale reads (also known as bounded staleness reads) can execute with lower latency because they can serve data from a timestamp in the recent past and do not have to wait for ongoing writes to be completed. This allows the application to trade off some consistency for lower latency, which is suitable for this scenario.

It Should be B. Since the application is more sensitive to latency and less sensitive to consistency performing stale reads is the best choice here. It will provide low latency at the cost of potentially returning stale data.

Should be B

B is correct

B is correct

B is correct

in my humble opinion it's D because the application must write on user contacts table.

B is right, data consistency is less sensitive.

B is the correct answer

"Your application takes an input from a user and publishes it to the user's contacts" What does "publishes" mean? If "write to database" than my vote is D

B is correct answer here.