C100DBA Philosophy and Features Practice Question
Which of these best describes MongoDB's approach to the CAP theorem?
⚠ Common exam trap
Candidates often incorrectly label MongoDB as an AP system because of its flexibility, forgetting that the default configuration prioritizes consistency during primary elections in a replica set.
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
✓
It prioritizes consistency and partition tolerance (CP).
MongoDB is primarily a CP (Consistency and Partition Tolerance) system, though it allows flexible configuration. In the event of a network partition, the system prioritizes consistency by electing a new primary only if a majority can agree. By allowing clients to configure read/write concerns, MongoDB lets developers trade off between immediate consistency and availability, enabling them to tune the database to match the specific requirements of their application's workload and regional deployment.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
It is an AP system that ignores consistency entirely.
Why it's wrong here
MongoDB is not purely AP; it provides strong consistency guarantees through its replica set elections and write concern options. It does not ignore consistency. In fact, it provides mechanisms for developers to enforce strict consistency where required, even in the face of network partitions.
- ✓
It prioritizes consistency and partition tolerance (CP).
Why this is correct
MongoDB is fundamentally a CP system, as it sacrifices availability during the short window of a primary election to ensure that all reads and writes are consistent. By requiring a majority of nodes to agree, it maintains the integrity of the data across the cluster.
- ✗
It ignores the CAP theorem to improve performance.
Why it's wrong here
The CAP theorem is a fundamental constraint for distributed systems. MongoDB does not ignore it; instead, it provides tools like read and write concerns to let developers choose where to sit on the spectrum between availability and consistency based on their specific business needs.
- ✗
It is a CA system that never allows partitions.
Why it's wrong here
No distributed system can be a CA system if it wants to handle network partitions. MongoDB assumes that network partitions will occur in a distributed environment and handles them by favoring consistency, meaning it cannot be a CA system by definition in the CAP framework.
About these practice questions
Courseiva writes every C100DBA question from scratch — 222 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official MongoDB exam blueprint
This C100DBA practice question is part of Courseiva's free MongoDB 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 C100DBA exam.