What is NoSQL?

What is NoSQL?


  • NoSQL databases are widespread, integral to our daily lives.
  • The term stands for “non-SQL” or “Not Only SQL.”
  • They handle unstructured and semi-structured data through various models.
  • Maor users include Netflix, Amazon, Google, etc.
  • NoSQL offers flexibility, scalability, cost-effectiveness, and high performance.
  • Ideal for IoT, mobile apps, online stores, social media, etc.
  • Differs from SQL in type, structure, query language, schema, etc.

NoSQL databases are everywhere. It might sound surprising but they are intertwined with our daily lives. In 2023, the global NoSQL market size was valued at around $9.86 billion. It is expected to grow at a CAGR of approximately 28.1%, reaching about $86.3 billion by 2032

What leads to such massive popularity and what exactly are NoSQL databases? Read ahead to find out!

What is NoSQL?

NoSQL is a type of database that stores and manages data differently than traditional relational databases. The term NoSQL stands for “Not Only SQL” or “non-SQL.” These types of databases don’t store data into the rows and columns format used by SQL databases. The term “not only SQL” means NoSQL can contain SQL data and beyond.

NoSQL databases are particularly helpful to contain large amounts of unstructured and semi-structured data. Such data is common for large web applications and big data applications. They store data in one house structures like JSON documents. They allow for flexible data models, quick iteration, and have the ability to scale out across multiple servers to handle large datasets.

Also Read: Python Developer Salary for Freshers and Experienced

Types of NoSQL Database

To perfectly understand what a NoSQL database is, it is also important to understand the types of NoSQL databases. There are 4 main types of NoSQL databases:

  • Key-Value Stores: These are the simplest form of NoSQL databases. Here each item is stored as a key paired with its value. They are highly useful for scenarios where you need to quickly look up for something by key. Take caching sessions and user settings as two of such scenarios. Examples of this type of NoSQL database include Redis and DynamoDB.
  • Document Stores: These databases store data in documents instead of rows and columns. They use document formats like JSON, XML, or BSON to store data. They are flexible and can contain nested data. These are particularly useful for content management systems (like WordPress) and user profiles where each document can vary in structure. MongoDB and CouchDB are two popular examples of such databases.
  • Wide-Column Stores: Unlike traditional databases, these store data in columns only (no rows are involved). They are optimal for querying large datasets of rows while needing only a few columns. They work well for analyzing large volumes of data quickly, like in big data analytics. Apache Cassandra and HBase are types of such databases. 
  • Graph Databases: These are used for storing data whose relations are best represented as a graph consisting of edges, nodes, and properties. You can use these in situations where you need to navigate relationships quickly or interconnected data like social networks and recommendation engines. You can consider any object, place or even yourself as a node. And an edge is the relationship between the nodes. Neo4J and Amazon Neptune are two of the most popular Graph databases.

Features of NoSQL

NoSQL databases are designed to offer flexible and scalable solutions for data storage. They are especially useful while dealing with large or evolving unstructured and semi-structured datasets. Here are some key features of NoSQL:

  • Flexible Data Models: Unlike traditional databases that require a fixed table structure, NoSQL databases allow you to store data in different formats. This means you can adjust your data structures according to your needs without redesigning the entire database.
  • No Fixed Schema: You don’t need to define a strict schema or data model in NoSQL databases. They use dynamic schema and allow for quick iteration. This lets you easily handle unstructured and semi-structured data that don’t follow any fixed schema.
  • High Availability: Many NoSQL databases are designed to be fault-tolerant. It means that they continue to operate even if a part of the system fails. They achieve this through data replication and distribution across multiple servers.
  • Scalability: You can easily scale out NoSQL databases by using distributed architectures. This means you can add more servers easily to handle more data or traffic without disrupting your existing setup.
  • High Performance: NoSQL databases are optimized for specific data models and access patterns that can lead to higher performance for certain tasks like large-scale web applications.

Also Read: Python Developer: Roles, Responsibilities & Job Description

Use Cases and Applications of NoSQL

NoSQL databases have a wide range of use cases and applications due to its extensive features. Here are some use cases you must know about:

  • NoSQL databases are great for IoT devices because they can handle huge amounts of real-time data from various devices. Take a smart home system for example. It might use NoSQL to process data from sensors like thermostats or security cameras to make real-time decisions.
  • Mobile apps often need to manage lots of user data. These include location, preferences, and activity logs. NoSQL databases help to manage such data by quickly storing and retrieving such data. They improve app responsiveness and user experience.
  • Online stores use NoSQL databases to manage dynamic product catalogs and customer profiles. This helps them adjust their inventory in real-time and offer personalized shopping experiences based on customer preferences and their behavior.
  • NoSQL is used in gaming platforms to handle user information, game states, and other information like high scores. These platforms use NoSQL databases to support massive numbers of players and real-time game status updates without slowing down.
  • Websites and apps that handle a lot of content, like news sites or social media platforms, use NoSQL to manage diverse types of data. These data include articles, user comments, etc. This flexibility helps them easily scale and adapt to user demands.  
  • NoSQL databases can quickly process data as it comes in. They are useful in scenarios like fraud detection where you need to act fast. They help businesses analyze large streams of data instantly to make informed decisions. 
  • Social media platforms deal with enormous amounts of user-generated data and interactions. NoSQL databases enable them to store and manage this varied data efficiently. It ensures smooth performance even during high traffic periods.

Companies that Use NoSQL Databases

  • Netflix uses NoSQL for managing user data (viewers history, content recommendation, etc.) and enhancing personalized experiences around the world.
  • Uber uses it for handling ride-sharing data and ensuring real-time ride matching.
  • Airbnb uses NoSQL for managing bookings, property listing, and customer profiles.
  • Amazon relies on NoSQL for e-commerce operations, handling inventory, user data, and transaction records globally.
  • Facebook uses it for managing large amounts of unstructured data like posts, comments, and likes.
  • Google uses NoSQL for AdWords and personalized services to ensure quick data processing.

Also Read: How Does SQL Work?

How Do NoSQL Databases Work?

As we already know, NoSQL databases operate differently than traditional databases. They use various data models like key-value pairs, documents, column-family, or graphs to organize and store data. 

When data is inserted into a NoSQL database, it’s typically stored in a format optimized for the chosen data model. Retrieving data involves querying the database using APIs or query languages specific to the database type. It then fetches the requested data based on the query criteria. 

NoSQL databases often distribute data across multiple servers. They allow for scalability and fault tolerance. Additionally they may employ techniques such as sharding and replication to ensure high availability and performance.

Advantages of NoSQL

  • Flexibility: No fixed schema, easy modifications.
  • Scalability: Easily scale out with additional servers.
  • Cost-effective: Lower hardware costs, more data management.
  • Performance: High performance for specific data and queries.

Disadvantages of NoSQL

  • Maturity: Newer tech, lacks some stability and features.
  • Support: Community support may not match as of SQL’s.
  • Query Complexity: Less efficient for complex queries.
  • Consistency: Sacrifices consistency for availability and partition tolerance (CAP theorem).

Coding with NoSQL: Sample Code

Below we can see a sample code that demonstrates the use of NoSQL databases. We will use MongoDB, one of the most popular NoSQL databases. This example shows how to connect to a MongoDB database, insert a document, and retrieve documents from the collection:

from pymongo import MongoClient

# Connect to the MongoDB server running on localhost

client = MongoClient(‘localhost’, 27017)

# Connect to a database named ‘testdb’

db = client[‘testdb’]

# Connect to a collection named ’employees’

collection = db[’employees’]

# Insert a new document into the ’employees’ collection

collection.insert_one({‘name’: ‘John Doe’, ‘age’: 28, ‘department’: ‘Finance’})

# Retrieve all documents in the ’employees’ collection

for employee in collection.find():


Explanation of the Code

  • To connect to MongoDB, use the MongoClient object specifying the host and port. 
  • Then, select a database and collection using db = client[‘testdb’] and collection = db[’employees’]. 
  • If they don’t exist, MongoDB creates them when data is stored
  • To insert a document, use collection.insert_one(…) with a Python dictionary.
  • For querying, use collection.find() to retrieve all documents in the collection, looping prints each one.

Also Read: What is SQL?

When should NoSQL be used?

NoSQL is ideal for:

  • Applications that require high scalability and flexibility.
  • Handling large volumes of data with varied structures.
  • Rapid development environments where schemas might change frequently.


StructureTable-basedDocument, key-value, graphs, etc.
Query LanguageStructured Query Language (SQL)Varied, often uses JSON-like syntax
ScalabilityVertical (Scaling up by adding more resources to a single server)Horizontal (Scaling out by adding more servers to the database)
TransactionsACID (Atomicity, Consistency, Isolation, Durability) compliantCAP (Consistency, Availability, Partition tolerance) compliant
Use CasesComplex queries and joinsLarge sets of distributed data
ExamplesMicrosoft SQL, OracleMongoDB, Cassandra


AspectRDBMS (Relational Database Management System)NoSQL (Not Only SQL)
Data StructureStructured with rows and columnsFlexible, uses key-value, graph, etc.
ScalabilityVertical (Scaling up by adding more resources to a single server)Horizontal (Scaling out by adding more servers to the database)
Query LanguageSQLDepends of the specific NoSQL database, often proprietary
ACID ComplianceGenerally fully ACID compliantVaries by implementation, may not fully support ACID properties
JoinsSupported, typically through SQLLimited or no support for complex joins
TransactionsFully supportedMay lack support for transactions or have limited transaction capabilities
Use CasesBest for structured data with complex relationships and transactionsIdeal for semi-structured or unstructured data, high-volume, and distributed systems


As we discussed, NoSQL databases are integral to our daily lives. And with time, their impact is expected to increase. While they don’t replace traditional SQL databases, they are increasingly used alongside them to handle specific, often more flexible, data requirements.

Today, the trend is towards a technology-agnostic approach where the choice of database technology is driven more by the specific needs of the application rather than the size or type of the organization. Therefore, understanding the capabilities of NoSQL is essential for developers and businesses aiming to use data effectively and make the most of it.

Frequently Asked Questions

What is NoSQL?

  • NoSQL stands for “Not Only SQL” or “non-SQL.”
  • It’s a type of database that stores and manages data differently from traditional relational databases.
  • NoSQL databases don’t use the rows and columns format of SQL databases.
  • They are particularly helpful for containing large amounts of unstructured and semi-structured data.

What are the main types of NoSQL databases?

  • Key-Value Stores: Simplest form, with items stored as key-value pairs.
  • Document Stores: Data stored in documents instead of rows and columns, using formats like JSON or XML.
  • Wide-Column Stores: Store data in columns only, optimal for querying large datasets of rows.
  • Graph Databases: Used for storing data represented as graphs of nodes, edges, and properties.

What are the advantages of using NoSQL databases?

  • Flexible data models allow for storing data in different formats.
  • No fixed schema requirement, enables quick iteration and handling of unstructured data.
  • High availability achieved through fault-tolerant designs and data replication.
  • Scalability by easily adding more servers to handle increased data or traffic.

Where are NoSQL databases commonly used?

  • IoT devices for handling real-time data from various sensors.
  • Mobile apps to manage user data.
  • Online stores for dynamic product catalogs and personalized shopping experiences.
  • Gaming platforms to support massive numbers of players and real-time status updates.
  • Content-heavy websites and social media platforms for managing diverse types of data and interactions.