- A
Use a database export and import to regenerate indexes.
Why wrong: Export/import does not create missing composite indexes.
- B
Create a composite index in the Firebase Console or gcloud CLI.
Composite indexes are manually created and are required for multi-field queries.
- C
Restructure the data to use a single field for the filter.
Why wrong: This may not be practical and doesn't address the error.
- D
Enable the automatic index creation in the Firestore settings.
Why wrong: Automatic index creation only applies to single-field indexes.
Question 111 of 1,000
PCDOE Manage Database Solutions Practice Question
This PCDOE practice question tests your understanding of manage 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 Cloud Firestore database in Native mode is used for a mobile app. The app queries a collection with a composite filter on two fields. Queries are slow and the app shows an error that an index is required. What should the developer do?
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
✓
Create a composite index in the Firebase Console or gcloud CLI.
Cloud Firestore requires an index to support composite filters (queries filtering on multiple fields). When a query uses a composite filter and no matching index exists, Firestore returns an error indicating an index is required. The correct solution is to create the necessary composite index manually via the Firebase Console or the gcloud CLI, as Firestore does not automatically create composite indexes for queries with equality and range filters on different fields.
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 database export and import to regenerate indexes.
Why it's wrong here
Export/import does not create missing composite indexes.
- ✓
Create a composite index in the Firebase Console or gcloud CLI.
Why this is correct
Composite indexes are manually created and are required for multi-field queries.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Restructure the data to use a single field for the filter.
Why it's wrong here
This may not be practical and doesn't address the error.
- ✗
Enable the automatic index creation in the Firestore settings.
Why it's wrong here
Automatic index creation only applies to single-field indexes.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the misconception that Firestore automatically creates all necessary indexes, but in reality, only single-field indexes are auto-created; composite indexes must be manually defined by the developer.
Detailed technical explanation
How to think about this question
Firestore uses indexes to ensure query performance and scalability. Composite indexes are defined on a collection or collection group and specify the fields and sort orders for queries that filter on multiple fields. When a query uses a composite filter (e.g., `where('fieldA', '==', value).orderBy('fieldB')`), Firestore checks for an existing composite index; if none exists, the query fails with an error. The developer must create the composite index manually, which can be done via the Firebase Console's Indexes tab or using the `gcloud firestore indexes composite create` command.
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.
- →
Manage Database Solutions — study guide chapter
Learn the concepts, then practise the questions
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Manage Database Solutions practice questions
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FAQ
Questions learners often ask
What does this PCDOE question test?
Manage Database Solutions — This question tests Manage Database Solutions — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Create a composite index in the Firebase Console or gcloud CLI. — Cloud Firestore requires an index to support composite filters (queries filtering on multiple fields). When a query uses a composite filter and no matching index exists, Firestore returns an error indicating an index is required. The correct solution is to create the necessary composite index manually via the Firebase Console or the gcloud CLI, as Firestore does not automatically create composite indexes for queries with equality and range filters on different fields.
What should I do if I get this PCDOE 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
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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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