Design innovative, scalable, and highly available cloud database solutions →mediumMultiple SelectObjective-mapped
PCDE Practice Question: Design innovative, scalable, and highly available cloud database solutions
You are designing a Spanner schema for a financial application that stores transactions for user accounts. To avoid hotspots and optimize performance, which TWO practices should you follow?
⚠ Common exam trap
A common misconception in Spanner is that monotonically increasing keys are safe, but they create hotspots. Candidates must remember that UUIDs or other high-cardinality, non-sequential keys are required for write distribution.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use the STORING clause in secondary indexes to include frequently accessed columns.
The STORING clause in a Spanner secondary index allows you to include non-key columns directly in the index, enabling index-only scans that avoid a back-join to the base table. This reduces read latency and resource consumption, which is critical for high-throughput financial transaction queries.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Store all data in a single table without interleaving.
Why it's wrong here
Not necessarily a best practice; interleaving can help for parent-child relationships.
- ✓
Use the STORING clause in secondary indexes to include frequently accessed columns.
Why this is correct
Optimizes read performance.
- ✓
Use a UUID as the primary key.
Why this is correct
Random distribution avoids hotspots.
- ✗
Use a monotonically increasing integer as the primary key.
Why it's wrong here
Causes hotspotting on the last tablet.
- ✗
Create secondary indexes without the STORING clause.
Why it's wrong here
Without STORING, additional reads to the base table are needed.
Go deeper
Related to this question
About these practice questions
One of 1,446 original PCDE practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCDE practice question is part of Courseiva's free Google Cloud certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PCDE exam.