- A
Use a single table for both Customers and Orders and filter by CustomerId.
Why wrong: This is not scalable and does not take advantage of interleaving.
- B
Use interleaved tables: make Orders an interleaved table under Customers.
Interleaved tables store Orders rows near their parent Customer, improving join performance.
- C
Denormalise the schema by embedding order details into the Customers table as repeated fields.
Why wrong: Spanner is relational; denormalisation with repeated fields is not supported. That's a BigQuery pattern.
- D
Include CustomerId as the first part of the Orders primary key.
This is required for interleaving; the child table's primary key must start with the parent's primary key.
- E
Create a secondary index on OrderDate in the Orders table.
A secondary index allows efficient queries by OrderDate without scanning all rows.
PDE Storing the Data Practice Question
This PDE practice question tests your understanding of storing the data. 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.
You are designing a Cloud Spanner schema for a global e-commerce application. The database will include a Customers table and an Orders table. To optimise performance for queries that join Customers with their Orders, which THREE design choices are recommended? (Choose 3.)
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 interleaved tables: make Orders an interleaved table under Customers.
Spanner interleaved tables store child rows physically close to parent rows, improving join performance. Including the parent's primary key as the first part of the child's primary key is required for interleaving. Secondary indexes on non-key columns are also needed for efficient lookups.
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 a single table for both Customers and Orders and filter by CustomerId.
Why it's wrong here
This is not scalable and does not take advantage of interleaving.
- ✓
Use interleaved tables: make Orders an interleaved table under Customers.
Why this is correct
Interleaved tables store Orders rows near their parent Customer, improving join performance.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Denormalise the schema by embedding order details into the Customers table as repeated fields.
Why it's wrong here
Spanner is relational; denormalisation with repeated fields is not supported. That's a BigQuery pattern.
- ✓
Include CustomerId as the first part of the Orders primary key.
Why this is correct
This is required for interleaving; the child table's primary key must start with the parent's primary key.
Related concept
Read the scenario before looking for a memorised answer.
- ✓
Create a secondary index on OrderDate in the Orders table.
Why this is correct
A secondary index allows efficient queries by OrderDate without scanning all rows.
Related concept
Read the scenario before looking for a memorised answer.
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 PDE 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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Storing the Data — study guide chapter
Learn the concepts, then practise the questions
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FAQ
Questions learners often ask
What does this PDE question test?
Storing the Data — This question tests Storing the Data — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use interleaved tables: make Orders an interleaved table under Customers. — Spanner interleaved tables store child rows physically close to parent rows, improving join performance. Including the parent's primary key as the first part of the child's primary key is required for interleaving. Secondary indexes on non-key columns are also needed for efficient lookups.
What should I do if I get this PDE question wrong?
Identify which PDE 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 PDE 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 PDE exam.
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