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10 top NoSQL database recently asked interview questions

1) Who are involved in developing NoSQL ?

Amazon and Google Papers

2) What is NoSQL?

Which we will use on non-relationla databases. Like columnar databases. By using NOSQL we can query data from non-relational databases.

3) What are unique features of NoSQL databases?

-There is no concept of relationship between records
-They need UN-structural data
-They do not store data that individual records do not have relationship with each other.

4) How NoSQL databases are faster than traditional RDBMS?

-Stores database on multiple servers,rather storing whole database in a single server
-Adding replicas on other servers, we can retrieve data faster, even one of the server crashes

5) What are the UNIQUE features of NoSQL?

-ACID complaint

6) What are the characteristics of good NoSQL product?

  • High availability: Fault tolerance when a single server goes down
  • Disaster recovery: For when a data center goes down, or more likely someone digs up a network cable just outside the data center
  • Support: Someone to stand behind a product when it goes wrong (or it's used incorrectly!)
  • Services: Product experts who can advise on best practices and help determine how to use a product to address new or unusual business needs
  • Ecosystem: Availability of partners, experienced developers, and product information — to avoid being locked into a single vendor's expensive support and services contract

7) Reasons to go for NoSQL databases?

An RDBMS can not fit for all of the enterprise requirements.
-Big data
-Schema Redesign overhead
-Unstructured data explosion
-It avoids Sparse data problem (RDBMS will use space for NULL values. But, NOSQL will ignore NULL values)
-Dynamically changing relationships between attributes

8) Benefits of NoSQL?

-Faster solutions for new generation problems
-Lower cost
-Modern computer systems don't exist in a vacuum; they're always communicating with someone or something. NoSQL databases are commonly paired with particular complementary computer software, from search engines to semantic web technologies and Hadoop. Leveraging these technologies can make deployment of NoSQL more productive and useful.

9) How many core types of NOSQL databases?

Columnar: Extension to traditional table structures. Supports variable sets of columns (column families) and is optimized for column-wide operations (such as count, sum, and mean average).

Key-value: A very simple structure. Sets of named keys and their value(s), typically an uninterpreted chunk of data. Sometimes that simple value may in fact be a JSON or binary document.

Triple: A single fact represented by three elements:

The subject you're describing
The name of its property or relationship to another subject
The value — either an intrinsic value (such as an integer) or the unique ID of another subject (if it's a relationship) For example, Adam likes Cheese. Adam is the subject, likes is the predicate, and Cheese is the object.

Document: XML, JSON, text, or binary blob. Any treelike structure can be represented as an XML or JSON document, including things such as an order that includes a delivery address, billing details, and a list of products and quantities.

10) What are the most modern databases?

In-memory and flash databases: Some great advances have been made in real-time online transaction processing (OLTP) and analytics using in-memory databases. In-memory databases are very specialized and are targeted to particular problem domains. NoSQL databases that take advantage of flash or memory caching to aid real-time analytics.

Complex proprietary stacks: NoSQL software such as Oracle NoSQL, MarkLogic, Microsoft's Document DB, and IBM Cloudant, though.

NewSQL: This is a new database access paradigm. It applies the software design lessons of NoSQL to RDBMS, creating a new breed of products, which is a great idea, but fundamentally these products still use traditional relational math and structures, which is why they aren't included. 


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