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Interview Questions

MongoDB Interview Questions and Answers

MongoDB Interview Questions and Answers

MongoDB Interview Questions and Answers

MongoDB Interview Questions and Answers for beginners and experts. List of frequently asked MongoDB Interview Questions with answers by Besant Technologies. We hope these MongoDB interview questions and answers are useful and will help you to get the best job in the networking industry. This MongoDB interview questions and answers are prepared by MongoDB Professionals based on MNC Companies expectation. Stay tune we will update New MongoDB Interview questions with Answers Frequently. If you want to learn Practical MongoDB Training then please go through this MongoDB Training in Chennai &  MongoDB Training in Bangalore.

MongoDB Interview Questions and Answers

Besant Technologies supports the students by providing MongoDB interview questions and answers for the job placements and job purposes. MongoDB is the leading important course in the present situation because more job openings and the high salary pay for this MongoDB and more related jobs. These are top MongoDB interview questions and answers, prepared by our institute experienced trainers.

MongoDB Interview Questions and Answers for the job placements

Here are the list of most frequently asked MongoDB Interview Questions and Answers in technical interviews. These questions and answers are suitable for both freshers and experienced professionals at any level. The questions are for intermediate to somewhat advanced MongoDB professionals, but even if you are just a beginner or fresher you should be able to understand the answers and explanations here we give.

Q1). What is MongoDB (frequently asked in mongodb interview questions)?

MongoDB is basically a database, essentially in a document form that entails high performance, effortless ascendancy and comfortably attainability.

Q2). Explain the term Namespace.

BSON (Binary Interchange and Structure Object Notation) elements are usually stored in database collection. The integration of collection and database is known as a namespace.

Q3). What is a replica set?

A replica set comprises of one primary and another secondary node. In between, all data replicates.

Q4). While creating a schema in this database what are the things you should take note of?

First, assess user requirement.

Combine or separate the document as per requirement.

The schema should be optimized if the cases occur frequently.

Aggregation in the schema to be performed.

Q5). What is command syntax?

When you insert a document, the command syntax is database.collection.insert (document)

Q6). Explain the indexes of this database

These are special structures in MongoDB to store a small quantum of data in the value of a specific field or set of fields.

Q7). Can removing an object attribute affect the database?

Yes, the object attribute is deleted. So you better eliminate the attribute and save the object again.

Q8). Clarify what happens when an index does not fit into RAM?

When the RAM finds it not able to accommodate an index due to the volume, MongoDB comes to rescue to read the index more speedily than the RAM.

Q9). Explain storage encryption

All the MongoDB data are encrypted on the storage to make sure that protected data can be accessed by none other than authorized processes.

Q10). Explain Aggregation Pipeline.

The aggregation tasks are performed within this structure. The pipeline is an abstract conduit to convert documents into aggregated results.

Q11). Are MongoDB and MySQL are the same?

Both are free and open source database. But there are operational differences between them.

Q12). Mention the language script of MongoDB

The language of MongoDB is C++. C extension is also used by some drivers for better performance.

Q13). What is NoSQL database? Explain various types of NoSQL databases

It is virtually a structure to store and retrieve data which is designed except in the tabular arrangement and applied in relational databases like SQL, Oracle etc.

It can be divided into 4 basics;

  • Document-centric
  • Key value
  • Graph
  • Column-oriented

Q14). Does the database have tables to store records?

Not at all. MongoDB uses Collections to store data.

Q15). In case the shard is slow or down and you are doing a query, how will you handle it?

Obviously, the query will backlash with an error message provided you set a partial query. Mongos will wait for a response, shard being slow.

Q16). Define sharding

In sharding, data records are stored amongst multiple machines. Horizontal database or search engine is created. Each respective partition is termed as a shard.

Q17). Can you highlight the role of a profiler?

A database profiler is inherent in MongoDB that reflects performance features of one and all activities against the database. With the help of profiler, queries and write operations that certainly are moderate than assumed. These statistics are utilized to ascertain the requirement of an index.

Q18). ave you ever heard of 32-bit nuances?

An extra memory mapped file is made agile in journaling. It will, in turn, delimit DB size of 32 bit builds. Presently, journaling is not specified on 32 bit systems.

Q19). Can you explain tractions/locking?

Customary locking or for that matter composite tractions with rollback is rarest of rare in MongoDB. The reason is that it is depicted to be light in weight, brisk and inevitable in its presentation. If a system is used with many servers, the very performance is improved remarkably.

Q20). Account for the duration of replica set failover?

10 to 30 seconds duration is enough for other members to let down the primary and replaced by another primary. The cluster is obviously not able to perform the primary operations (write and read). Ultimately, compatible queries can be touch-based to secondaries at any given point of time within the time frame.

Q21). Are the terms Master or Primary same?

Yes, they are alternate terms. Master or Primary is a node or member, which is as of now a Primary and it helps process the writes for the replica set. Also, another member has the option to become Primary in the event of failover of a replica set.

Q22). Also, explain a Secondary or a Slave

Application of operations from the recent Primary is called a Secondary node or member. Tailing the replication oplog is the essence. Copying Primary to Secondary can be chronologically misplaced. Although, the proximity of the Secondary will be next to the current, which can be a few milliseconds on a LAN.

Q23). Data files can be smaller. But here, these are too large. Why?

A hostile preallocation of the reserved area is enacted by MongoDB in view of fragmentation of file system.

Q24). Can you isolate cursors from the Write operations?

The snapshot method can be implemented on a cursor to detach an operation for a particular case. The index is intervened by snapshot and ensures that each document will be returned by the query at least once.

Q25). Explain the term Gridfs

It is a specification, leading to storage and recovery of files which is in excess of the size of the BSON document of 16 GB. Gridfs helps in defragmenting a file, thus far concentrated in one bond. Each fragment is stored as a separate document.

Q26). In what way MongoDB go for concurrency (a key question among mongodb interview questions)?

Reader-Write locks are used which enables concurrent readers to have access to a resource viz., database or collection and distinctive permission is given to a single write operation.

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