- A
Use parent-child interleaving for Order and OrderItems
Interleaving optimizes joins between parent and child tables.
- B
Use a monotonically increasing primary key for Order
Why wrong: Monotonically increasing keys cause hotspots in Spanner.
- C
Store OrderItems in a separate database
Why wrong: Unnecessary; Spanner supports interleaved tables.
- D
Use UUID as primary key for Order
UUID distributes writes evenly, avoiding hotspots.
- E
Denormalize OrderItems into an array column in Order
Why wrong: Spanner supports array columns, but this breaks normal form and may limit query flexibility.
Question 201 of 1,000
PCDOE Design and Plan Database Solutions Practice Question
This PCDOE practice question tests your understanding of design and plan database solutions. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company is designing a schema for Cloud Spanner for an order management system. They need to ensure efficient joins between Order and OrderItems tables. Which TWO design practices should they adopt? (Choose 2)
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 parent-child interleaving for Order and OrderItems
Parent-child interleaving places child rows physically near parent rows, enabling efficient joins. Using the OrderId as the primary key of Order and also as the first part of the primary key of OrderItems (with a line item identifier) allows for strongly consistent interleaved queries.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Use parent-child interleaving for Order and OrderItems
Why this is correct
Interleaving optimizes joins between parent and child tables.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Use a monotonically increasing primary key for Order
Why it's wrong here
Monotonically increasing keys cause hotspots in Spanner.
- ✗
Store OrderItems in a separate database
Why it's wrong here
Unnecessary; Spanner supports interleaved tables.
- ✓
Use UUID as primary key for Order
Why this is correct
UUID distributes writes evenly, avoiding hotspots.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Denormalize OrderItems into an array column in Order
Why it's wrong here
Spanner supports array columns, but this breaks normal form and may limit query flexibility.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
- Use explanations to understand the rule behind the answer.
TExam Day Tips
- Underline the problem statement mentally.
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
Got this wrong? Here's your next step.
Identify which PCDOE exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
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FAQ
Questions learners often ask
What does this PCDOE question test?
Design and Plan Database Solutions — This question tests Design and Plan Database Solutions — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use parent-child interleaving for Order and OrderItems — Parent-child interleaving places child rows physically near parent rows, enabling efficient joins. Using the OrderId as the primary key of Order and also as the first part of the primary key of OrderItems (with a line item identifier) allows for strongly consistent interleaved queries.
What should I do if I get this PCDOE question wrong?
Identify which PCDOE exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
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Last reviewed: Jul 4, 2026
This PCDOE 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 PCDOE exam.
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