Search Interview Questions
| More than 3000 questions in repository.|
There are more than 900 unanswered questions.
Click here and help us by providing the answer.
Have a video suggestion.
Click Correct / Improve and please let us know.
|Mongodb - Interview Questions and Answers for 'Epam' - 1 question(s) found - Order By Newest|
|Ans. Document Oriented: |
MongoDB stores the main subject in the minimal number of documents and not by breaking it up into multiple relational structures like RDBMS. For example, it stores all the information of a computer in a single document called Computer and not in distinct relational structures like CPU, RAM, Hard disk, etc.
Indexing: Without indexing, a database would have to scan every document of a collection to select those that match the query which would be inefficient. So, for efficient searching Indexing is a must and MongoDB uses it to process huge volumes of data in very less time.
Scalability: MongoDB scales horizontally using sharding (partitioning data across various servers). Data is partitioned into data chunks using the shard key, and these data chunks are evenly distributed across shards that resides across many physical servers. Also, new machines can be added to a running database.
Replication and High Availability: MongoDB increases the data availability with multiple copies of data on different servers. By providing redundancy, it protects the database from hardware failures. If one server goes down, the data can be retrieved easily from other active servers which also had the data stored on them.
Aggregation: Aggregation operations process data records and return the computed results. It is similar to the GROUPBY clause in SQL. A few aggregation expressions are sum, avg, min, max, etc
|Help us improve. Please let us know the company, where you were asked this question :|
|Like Discuss Correct / Improve   Asked in 1 Companies|
|Difference between == and .equals() ?|
|Why is String immutable in Java ?|
| Explain the scenerios to choose between String , StringBuilder and StringBuffer ?|
What is the difference between String , StringBuilder and StringBuffer ?
|What are the difference between composition and inheritance in Java?|
|Does garbage collection guarantee that a program will not run out of memory?|
|Why Char array is preferred over String for storing password?|
|What are different ways to create String Object? Explain.|
|Why do we need Inner classes ? Cant we just work with outer classes wherever we implement Inner classes ?|
|What is the difference between declaration, instantiation and initialization ?|
|What is the difference between Encapsulation and Abstraction?|