FC0-U71 Data and Database Fundamentals Practice Question
Which TWO of the following are examples of popular relational database management systems (RDBMS)? (Select TWO.)
⚠ Common exam trap
FC0-U71 often tests whether candidates can distinguish RDBMS from NoSQL by name recognition alone — MongoDB, Cassandra, and Redis are frequently mistaken for relational databases because they are all 'databases,' but only MySQL and PostgreSQL use relational tables and SQL.
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
✓
MySQL
MySQL (B) is a widely used open-source relational database management system that stores data in tables with rows and columns and supports SQL, making it a correct example of an RDBMS. PostgreSQL (D) is likewise a popular open-source relational database management system that enforces ACID transactions, foreign keys, and SQL compliance, so it also qualifies as an RDBMS. The remaining options are non-relational: Cassandra (A) is a distributed wide-column NoSQL store, MongoDB (C) is a document-oriented NoSQL database, and Redis (E) is an in-memory key-value data store, none of which implement the relational table-and-SQL model.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Cassandra
Why it's wrong here
Cassandra is a wide-column NoSQL distributed store, using a partitioned ring rather than relational tables with SQL joins and foreign keys. It is tempting because it handles massive write volumes across nodes. Cassandra would be correct for high-availability, multi-region NoSQL workloads, not RDBMS selection.
- ✓
MySQL
Why this is correct
MySQL is a widely deployed open-source relational database management system, storing data in tables with SQL querying and ACID transactions. It satisfies the stem's requirement for a popular RDBMS example, distinguishing it from NoSQL or non-relational alternatives.
- ✗
MongoDB
Why it's wrong here
MongoDB is a document-oriented NoSQL database storing BSON documents in collections, lacking fixed relational schemas and SQL joins. Its popularity makes it a tempting distractor. MongoDB is correct for flexible-schema, horizontally scaled document workloads, not for the RDBMS examples the question requests.
- ✓
PostgreSQL
Why this is correct
PostgreSQL is an open-source object-relational database that stores data in tables with rows and columns, enforcing primary and foreign key relationships through SQL. This satisfies the stem's requirement for a relational database management system, as it provides full ACID compliance and structured query support.
- ✗
Redis
Why it's wrong here
Redis is an in-memory key-value data store, holding structures such as strings, hashes and lists without SQL schemas or relational joins. Its speed tempts candidates. Redis is the right pick for caching, session storage or pub/sub messaging, not as an example of a relational database management system.
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Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CompTIA exam blueprint
This FC0-U71 practice question is part of Courseiva's free CompTIA 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 FC0-U71 exam.