Google Cloud Professional Cloud Developer — Question 99

You are developing an ecommerce application that stores customer, order, and inventory data as relational tables inside Cloud Spanner. During a recent load test, you discover that Spanner performance is not scaling linearly as expected. Which of the following is the cause?

Answer options

• A. The use of 64-bit numeric types for 32-bit numbers.
• B. The use of the STRING data type for arbitrary-precision values.
• C. The use of Version 1 UUIDs as primary keys that increase monotonically.
• D. The use of LIKE instead of STARTS_WITH keyword for parameterized SQL queries.

Correct answer: C

Explanation

The correct answer is C because using Version 1 UUIDs as primary keys can lead to hotspots in Cloud Spanner, which negatively affects performance by not distributing writes evenly. Options A and B do not directly impact performance in the same way, and option D may have performance implications but is not the primary cause of the scaling issue.