Couchbase, an open source multimodel NoSQL document-oriented database designed specifically to power interactive web apps, is an attractive option when building complex cloud apps.

Our Couchbase Interview Questions and answers blog serves as an invaluable resource when preparing for interviews involving this platform.

This blog presents key questions and responses you must prepare for during a Couchbase job interview.

Let’s use Couchbase’s unique approach and start working our magic now to prepare ourselves and ace any interviews!

1. What is Couchbase?

Couchbase is a distributed NoSQL database that automatically distributes data across commodity servers or virtual machines. It is designed for mission-critical applications that require high performance at scale.

2. What kind of data storage does Couchbase use?

Couchbase uses disk-based storage for data and includes a built-in data cache derived from Memcached. This ensures predictable, low-latency access for random reads and writes.

3. Can capacity be added or removed from a live Couchbase cluster?

Capacity can be added or removed from a live Couchbase cluster with no application downtime. The administrator UI allows any number of servers to be added or removed at once.

4. What is data replication in Couchbase?

Data replication in Couchbase is configurable and allows for continuous operations. It includes live rebalancing to ensure that data is evenly distributed across the cluster.

5. What is the role of the administrator UI in Couchbase?

The administrator UI in Couchbase allows adding or removing any number of servers to a live cluster without application downtime. It also provides monitoring and management tools for the group.

6. What is the Memcached protocol in Couchbase?

The Memcached protocol in Couchbase allows for an easy transition of existing applications to Couchbase Server without changing production code.

7. What is a full-text search in Couchbase?

Full-text search is a service in Couchbase that eliminates the need for additional technology in text tags and simplifies architecture. It uses the database change protocol (DCB) to update global secondary and full-text search indexes.

8. What is couch-based analytics?

Couch-based Analytics is a service in Couchbase that offers real-time access to data, eliminating the need for ETL processes and allowing immediate use of data.

9. What is the DCB protocol?

The DCB (Database Change Protocol) keeps global secondary indexes and full-text search indexes up-to-date in Couchbase.

10. What is XDCR in Couchbase?

XDCR (cross-datacentre replication) is a service in Couchbase that enables data replication from one cluster to another or across multiple groups.

It can be run unidirectionally, bi-directionally, or multi-directionally and offers memory-based copy at network speed, varying latency depending on distance and network speed.

11. What is the merge backup capability in Couchbase?

The merge backup capability in Couchbase allows for merging full and incremental backups, making database restorations more efficient.

It also provides for data storage on Amazon S3 or Microsoft Azure blob storage, allowing analytics services to run queries directly onto the stored data without moving it back into the Couchbase cluster.

12. What is multi-dimensional scaling in Couchbase?

Multi-dimensional scaling is a feature in Couchbase that allows for horizontal scaling and isolation of workloads. It provides analytics to run queries across two data sets: those stored on Couchbase and Amazon S3 or Microsoft Azure blob storage.

13. What are ORMs?

ORMs, or Object-Relational Mapping tools, are used to make relational systems easier for programmers. They allow for mapping objects to tables in a database, simplifying data access and manipulation.

14. What are the drawbacks of using ORMs?

While ORMs can simplify data access and manipulation, they are often slower to store and retrieve data than manual methods and are less performant than straight queries. Manual creation and changes are also more time-consuming and complex with ORMs.

15. What is JSON?

JSON, or JavaScript Object Notation, is a lightweight data format that is easy to read and write. Web development commonly uses it to transmit data between a server and a client.

16. What are the unique keys in Couchbase?

Unique keys in Couchbase are used to identify documents within a collection. They can be based on various data, such as email addresses, usernames, SKUs, or ISBNs. Prefixing keys with “user” or “type” is not strictly necessary, but it can make the key more accessible to read.

17. What are predictable keys in Couchbase?

Predictable keys in Couchbase make it easier to access specific documents within a collection. They are generated based on a particular piece of data, such as an email address or a hash.

18. What is the purpose of using behavior-driven design in Couchbase?

The purpose of using behaviour-driven design in Couchbase is to focus on creating multiple documents that point to a primary record. It is also recommended to increment the user count to add the direct copy and look at documents that store the ID.

19. What are some cons of using behaviour-driven design in Couchbase?

One con of using behaviour-driven design in Couchbase is that it increases the number of documents within the system.

20. What are some advantages of using separate documents for data storage in Couchbase?

Some advantages of using separate documents for data storage in Couchbase include faster application development by decoupling data from objects and creating object models and relationships.

21. What is the concept of user IDs in CouchBase?

The concept of user IDs in CouchBase allows for creativity and control by the programmer. Various methods for creating IDs can be used, such as using an email address or username as a key, incrementing accounts, and creating a lookup for the email address.

22. What is the use of views and indexes in CouchBase?

Views and indexes in CouchBase are primarily used for creating and retrieving users. Indexes can be used to maintain consistency but are eventually consistent and not in isolation.

23. What is a multi-get operation in CouchBase?

A multi-get operation in CouchBase allows for the generation of keys for multiple IDs and retrieval of an array of documents. All Couchbase SDKs support this operation and can be slightly faster than get functions.

24. What is the primary purpose of normalisation?

The primary purpose of normalisation is to avoid update anomalies, which can be prevented by updating multiple tables simultaneously.

25. What is denormalisation?

Denormalisation is storing data in a non-normalized form, which can result in data redundancy and inconsistencies.

26. What is a two-phase commit?

A two-phase commit is a process used in database transactions to ensure that multiple operations are completed atomically and that the database remains consistent.

27. What are the benefits of using a multi-get operation?

The benefits of using a multi-get operation include faster retrieval of multiple documents than performing separate get operations for each record and the ability to generate keys for various IDs with a single request. All Couchbase SDKs support this operation.

28. In what scenarios would using compound keys be beneficial in Couchbase?

Using compound keys can be beneficial in Couchbase when there is a need to break apartkeys for querying or sorting purposes or when there is a need to group related documents.

29. What operation allows for retrieving an array of documents with multiple IDs?

The multi-get operation allows for retrieving an array of documents with multiple IDs.

30. Besides views, How can compound keys be used in Couchbase?

Compound keys can be used creatively in Couchbase by combining multiple components to generate a key that can be used in views or index functions.

We trust this blog has provided you with useful insight into Couchbase. Those wanting to gain more information will find an abundance ofCouchBase interview questions and answers related to this popular database system herein.

Couchbase has proven itself as an efficient and dependable method for handling large volumes of complex data. As an open NoSQL database system, Couchbase can offer secure storage solutions to applications of all sizes and complexities.