Google Cloud Professional Data Engineer — Question 32

You are choosing a NoSQL database to handle telemetry data submitted from millions of Internet-of-Things (IoT) devices. The volume of data is growing at 100
TB per year, and each data entry has about 100 attributes. The data processing pipeline does not require atomicity, consistency, isolation, and durability (ACID).
However, high availability and low latency are required.
You need to analyze the data by querying against individual fields. Which three databases meet your requirements? (Choose three.)

Answer options

• A. Redis
• B. HBase
• C. MySQL
• D. MongoDB
• E. Cassandra
• F. HDFS with Hive

Correct answer: B, D, E

Explanation

HBase, MongoDB, and Cassandra are all designed to handle large volumes of unstructured data, making them suitable for IoT telemetry data. They provide high availability and low latency, which are essential for your requirements. In contrast, MySQL is a relational database that enforces ACID properties and is not optimized for the scale and flexibility needed in this scenario, while Redis is primarily an in-memory data structure store, which may not be suitable for persistent large-scale storage. HDFS with Hive is more suited for batch processing rather than real-time querying.