4 Essential NoSQL Interview Questions and Answers to Know

NoSQL Interview Questions

The editors at Solutions Review highlight the essential NoSQL interview questions and answers to know right now.

NoSQL encompasses a wide variety of different database technologies that were developed in response to a rise in the volume of data stored about users, objects, and products. NoSQL databases are great at taking into account the frequency in which this data is accessed, and performance and processing needs. Relational databases, on the other hand, were not designed to cope with the scale and agility challenges that face modern applications, nor were they built to take advantage of the cheap storage and processing power available today.

With this in mind, we’ve compiled this list of essential NoSQL interview questions and answers to save you time and help you ace your next interview. We compiled this resource by curating the most popular results from community forums like Quora and Reddit. This resource features a short list of basic NoSQL interview questions to prepare for. Prospective data management leaders may also want to consult our directory of top-rated NoSQL books as well.

NoSQL Interview Questions and Answers

Q: What are the key features of NoSQL?

A: When compared to relational databases, NoSQL databases are more scalable and provide superior performance, and their data model addresses several issues that the relational model is not designed to address:

  • Large volumes of structured, semi-structured, and unstructured data
  • Agile sprints, quick iteration, and frequent code pushes
  • Object-oriented programming that is easy to use and flexible
  • Efficient, scale-out architecture instead of expensive, monolithic architecture

Q: What is Polygot Persistence?

A: In 2006, Neal Ford coined the term polyglot programming to express the idea that applications should be written in a mix of languages. Ford presented this due to the fact that different languages are suitable for tackling different problems. Complex applications combine different types of problems, so picking the right language for each job may be more productive than trying to fit all aspects into a single language.

Q: How do NoSQL databases budget memory?

A: The Replication Node manages the data in a NoSQL DB store and is the main consumer of memory. The Java heap and cache size used by the Replication Node (RN) can be important performance factors as well. By default, the RN heap and cache are calculated by NoSQL DB based on the amount of memory available to the Storage Node (SN).

If the SN hosts more than one RN, the memory will be divided evenly between all RNs. If the number of Replication Nodes on a Storage Node changes, the per-RN memory will be recalculated dynamically. The percentage used for the heap is controlled by the rnHeapPercent Storage Node parameter.

Q: How do you script NoSQL configuration?

A: You may find that you want to build the same NoSQL DB configuration repeatedly for testing purposes. The Admin CLI commands can be scripted in several ways. Many uses of the Admin CLI are simple commands to initially configure a StorageNode. These are as amenable to scripting as any other UNIX commands. Interactive commands available in Java can be scripted in two ways: you can create a file containing the sequence of commands that you want to run or run them in a batch.

Timothy King
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