The answer is that all orders for that customer are automatically deleted. This occurs because Cloud Spanner interleaved tables enforce parent-child referential integrity at the storage level, meaning child rows are physically stored with their parent row. When a parent row in the Customers table is deleted, the database engine automatically performs a cascade delete on all interleaved child rows in the Orders table, without requiring an explicit ON DELETE CASCADE clause. On the Google Professional Cloud Database Engineer exam, this concept tests your understanding of how interleaving differs from traditional foreign key constraints—a common trap is assuming you need to manually script cascading deletes or that interleaving only affects query performance. Remember that interleaving is both a storage and integrity mechanism: the parent row owns its children, so deleting the parent removes the entire family. A useful memory tip is to think of interleaved tables as nested folders—deleting the folder deletes everything inside it.
PCDE Plan and manage database infrastructure Practice Question
This PCDE practice question tests your understanding of plan and manage database infrastructure. 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.
Exhibit
CREATE TABLE Customers (
CustomerId INT64 NOT NULL,
Name STRING(1024),
) PRIMARY KEY (CustomerId);
CREATE TABLE Orders (
CustomerId INT64 NOT NULL,
OrderId INT64 NOT NULL,
OrderDate DATE,
) PRIMARY KEY (CustomerId, OrderId),
INTERLEAVE IN PARENT Customers ON DELETE CASCADE;
Refer to the exhibit. A company creates these Cloud Spanner tables. What happens when a customer record is deleted?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
All orders for that customer are automatically deleted.
Option C is correct because Cloud Spanner enforces referential integrity through interleaved tables. When a parent row in the Customers table is deleted, all child rows in the Orders table that are interleaved under that customer are automatically deleted via a cascading delete. This behavior is inherent to the interleaved table structure, not an explicit ON DELETE CASCADE clause.
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.
✗
The deletion fails if there are orders.
Why it's wrong here
ON DELETE CASCADE allows deletion without failure; it cascades to child rows.
✗
The orders are deleted only if the order date is older than 30 days.
Why it's wrong here
Cascade deletes all child rows regardless of age; there is no condition.
✓
All orders for that customer are automatically deleted.
Why this is correct
Cascade delete removes all child rows associated with the deleted parent row.
Related concept
Read the scenario before looking for a memorised answer.
✗
The orders remain orphaned.
Why it's wrong here
Orphaned rows are not left; they are deleted due to CASCADE.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates may assume Cloud Spanner behaves like traditional relational databases (e.g., requiring explicit ON DELETE CASCADE or failing on foreign key violations), but interleaved tables automatically cascade deletes without any additional syntax.
Detailed technical explanation
How to think about this question
Interleaved tables in Cloud Spanner physically co-locate parent and child rows on the same split, optimizing join performance and ensuring atomic deletion of the entire hierarchy. The parent-child relationship is defined by the PRIMARY KEY of the child table, which must include the parent's primary key as a prefix. This design eliminates the need for explicit foreign key constraints or cascading delete statements, as the deletion is handled at the storage layer.
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.
TExam Day Tips
→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 exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Plan and manage database infrastructure — This question tests Plan and manage database infrastructure — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: All orders for that customer are automatically deleted. — Option C is correct because Cloud Spanner enforces referential integrity through interleaved tables. When a parent row in the Customers table is deleted, all child rows in the Orders table that are interleaved under that customer are automatically deleted via a cascading delete. This behavior is inherent to the interleaved table structure, not an explicit ON DELETE CASCADE clause.
What should I do if I get this PCDE question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company has a parent-child relationship in Cloud Spanner. They want to minimize cross-table join latency. What should they use?
medium
✓ A.Interleaved tables
B.Cloud Functions
C.Stored procedures
D.Secondary indexes
Last reviewed: Jun 25, 2026
Question Discussion
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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.
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