SQL vs NoSQL: 5 Critical Differences

When choosing a modern database, one of the biggest decisions is picking a relational (SQL) or non-relational (NoSQL) data structure. Both systems offer unique advantages and cater to different needs, making the choice between them crucial for optimal data management.

SQL, or Structured Query Language, is a programming language with a traditional approach that allows relational databases that model predefined schemas to manage structured data like rows and tables. On the other hand, NoSQL, which stands for "Not Only SQL," offers a more flexible, non-relational approach, ideal for handling unstructured or dynamic data. As businesses evolve and data becomes increasingly diverse, understanding the core differences between SQL and NoSQL is important.

Here, we break down the most important distinctions and discuss the best SQL and NoSQL database systems available.

The five critical differences between SQL and NoSQL are:

SQL databases are relational, and NoSQL databases are non-relational.
SQL databases use structured query language (SQL) and have a predefined schema. NoSQL databases have dynamic schemas for unstructured data.
SQL databases are vertically scalable, while NoSQL databases are horizontally scalable.
SQL databases are table-based, while NoSQL databases are document, key-value, graph, or wide-column stores.
SQL databases are better for multi-row transactions, while NoSQL is better for unstructured data like documents or JSON.

Table of Contents

Introduction

What is SQL?

SQL is a domain-specific language used to query and manage data. It works by allowing users to query, insert, delete, and update records in relational databases. SQL also allows for complex logic to be applied through the use of transactions and embedded procedures such as stored functions or views.

What is NoSQL?

NoSQL stands for Not only SQL. It is a type of database that uses non-relational data structures, such as documents, graph databases, and key-value stores to store and retrieve data. NoSQL systems are designed to be more flexible than traditional relational databases and can scale up or down easily to accommodate changes in usage or load. This makes them ideal for use in applications

Why NoSQL is Used Over SQL

NoSQL is preferred over SQL in many cases because it offers more flexibility and scalability. The primary benefit of using a NoSQL system is that it provides developers with the ability to store and access data quickly and easily, without the overhead of a traditional relational database. As a result, development teams can focus on delivering features and core business logic faster, without worrying about the underlying data storage implementation.

Which is better SQL or NoSQL?

The decision of which type of database to use - SQL or NoSQL - will depend on the particular needs and requirements of the project. For example, if you need a fast, scalable, and reliable database for web applications then a NoSQL system may be preferable. On the other hand, if your application requires complex data queries and transactional support then an SQL system may be the better choice. Ultimately, there is no one-size-fits-all solution - it all comes down to what you need from your database and which type of system can provide that in the most efficient manner. It's best to research both options thoroughly before making a decision.

Below, learn in-depth about the most important distinctions between SQL vs NoSQL databases and the best systems available on the market.

Comparison of SQL vs NoSQL

With a basic understanding of what SQL vs NoSQL is, let's take a look at this quick comparison chart to see what sets the two apart:

Now that you understand the fundamentals, let's explore five key differences between SQL and NoSQL databases that can help you decide which technology best suits your data storage needs.

Database Architecture

At the most basic level, the biggest difference between these two technologies is that SQL databases are relational, while NoSQL databases are non-relational.

What are Relational Databases?

Relational databases use Structured Query Language (SQL) to store and retrieve data.

Relational databases (also called relational database management systems or RDBMSs) store data in rows and tables. These systems connect information from various tables with keys — unique identifiers that the database assigns to rows of data in tables. Primary keys and foreign keys facilitate this process.

What are Non-Relational Databases (NoSQL)?

Non-relational, or NoSQL databases are more flexible and don’t necessarily require the same rigid structure as SQL.

Non-relational databases store data just like relational databases. However, they don't contain any rows, tables, or keys. This type of database utilizes a storage model based on the type of data it stores.

Database Schemas and Query Languages

SQL databases use structured query language and have a pre-defined schema for defining and manipulating data. SQL is one of the most versatile and widely used query languages available, making it a safe choice for many use cases. It’s perfect for complex queries. However, SQL can be too restrictive. You have to use predefined schemas to determine your data structure before you can work with it. All of your data must follow the same structure, and this process requires significant upfront preparation. If you ever need to change your data structure, it would be difficult and disruptive to your whole system.

NoSQL databases have dynamic schemas for unstructured data and store data in many ways. You can use column-oriented, document-oriented, graph-based, or KeyValue stores for your data. This flexibility means that:

You can create documents without having to first define their structure.
Each document can have its own unique structure.
The syntax can vary from database to database.
You can add fields as you go.

Database Scaling

Another difference between SQL vs NoSQL databases is scaling. SQL databases are vertically scalable in most situations. That means you can increase the load on a single server by adding more CPU, RAM, or SSD capacity.

NoSQL databases are horizontally scalable. You can handle higher traffic via a process called sharding, which adds more servers to your NoSQL database. Horizontal scaling has a greater overall capacity than vertical scaling, making NoSQL databases the preferred choice for large and frequently changing data sets. For example, you might use a NoSQL database if you have large data objects like images and videos. An SQL database wouldn't be able to handle these objects as effectively, making it difficult to fulfill your data requirements.

Data Structure

SQL databases are table-based, where each field in a data record has the same name as a table column. This proves beneficial when performing multiple data transformations.

NoSQL databases are document, key-value, graph, or wide-column stores. These flexible data models make NoSQL databases easier for some developers to use.

Use Cases

SQL databases are better for multi-row transactions, while NoSQL is better for unstructured data like documents or JSON. SQL databases are also commonly used for legacy systems built around a relational structure.

You might use an SQL database for user-oriented applications with several join operations. SQL schema will help you establish ACID properties and improve data compatibility. These databases are also useful when quickly finding the data you need to complete a task.

You might use a NoSQL database for applications with dynamic data without join operations. NoSQL is also better suited for applications with missing data sets that won't impact business efficiency.

Some examples of SQL databases include MySQL, Oracle, PostgreSQL, and Microsoft SQL Server. NoSQL database examples include MongoDB, BigTable, Redis, Cassandra, HBase, Neo4j, and CouchDB.

When to use SQL vs NoSQL

It really comes down to the type of application you are building and the data requirements it entails. Understanding each database's unique features will help you decide which one is best for your project. It is also important to consider scalability and performance when making a decision on whether to use SQL or NoSQL. Knowing which database fits your needs can improve performance, ensure data integrity, and ultimately help you create a successful application.

In general, SQL databases are suitable for structured data, where data is consistent, and relationships between tables are well-defined. In contrast, NoSQL databases are suitable for semi-structured or unstructured data, where the data does not conform to a predefined schema, and relationships between data elements are not well-defined. SQL databases are typically used in applications that require complex queries and transaction management, whereas NoSQL databases are used in applications that require high performance and scalability, such as web applications and mobile apps.

Now that you know the key differences between SQL vs NoSQL databases, it’s time to explore the different options available for your workloads.

SQL Database Systems

Here are some of the most popular SQL database systems:

MySQL

Free and open-source
An extremely established database with a huge community, extensive testing, and lots of stability
Supports all major platforms
Replication and sharding are available
Covers a wide range of use cases

Oracle

Commercial database with frequent updates, professional management, and excellent customer support
Procedural Language/SQL or PL/SQL is the SQL dialect used
One of the most expensive database solutions
Works with huge databases
Simple upgrades
Transaction control
Compatible with all operating systems
Suitable for enterprises and organizations with demanding workloads

Microsoft SQL Server

A commercial database developed and managed by Microsoft
Transact SQL, or T-SQL, is the SQL dialect used
Only works with Windows and Linux
User-friendly
Difficult to make adjustments mid-process when finding errors
Excellent documentation
Works well for small-to-medium-sized organizations that want a commercial database solution without the cost of Oracle

PostgreSQL

Object-oriented database management system, meaning it’s a hybrid SQL/NoSQL database solution
Free and open-source
Compatibility with a wide range of operating systems
Active community and many third-party service providers
High ACID compliance
Uses pure SQL
Works best for use cases where data doesn’t support a relational model. It also works well for extra-large databases and when running complicated queries

NoSQL Database Systems

Here are a couple of the most popular NoSQL database systems:

MongoDB

By far the most popular NoSQL database, and for good reason
Free to use
Dynamic schema
Horizontally scalable
Excellent performance with simple queries
Add new columns and fields without impacting your existing rows or application performance
Works best for companies going through rapid growth stages or those with a lot of unstructured data
Lesser-known alternatives to MongoDB include Apache Cassandra, Google Cloud BigTable, and Apache HBase

Cassandra

Handles large amounts of data across commodity servers
High availability with no point of failure
Follows peer-to-peer architecture
Scalable
Open-source

How Integrate.io Helps With SQL/NoSQL Database Integration

Once you’ve decided on SQL or NoSQL databases, you need to move data into them! Data integration is a complex process that may present serious challenges. Do it wrong, and you could lose valuable data sets or face fines for non-compliance with data governance frameworks like GDPR and CCPA.

Integrate.io can help you overcome the challenges of data integration. This no-code data pipeline platform moves data sets from siloed sources into a supported database of your choice without lots of programming or data engineering.

Integrate.io has hundreds of built-in integrations that make it easy to work with your new database technology, whether you choose a SQL or NoSQL system. For example, the platform's out-of-the-box MongoDB connector ETLs data from a source to this popular database without the need to build data pipelines from scratch or hire additional engineers. The native connector extracts data from a source, transforms it into the correct format for MongoDB, and loads it into the database. Alternatively, you can ETL MongoDB data to a data warehouse for analytics and generate intelligence about your business for better decision-making.

Other Integrate.io benefits include:

World-class customer service
Easy data transformations
Compliance with data governance frameworks
Online tutorials, FAQs, and other resources

Integrate.io helps you integrate data to and from a supported SQL or NoSQL database. The no-code data pipeline platform streamlines integration for your particular use case, removing the pain points of moving data between two or more locations. Schedule a demo now.

FAQ: Understanding SQL vs NoSQL Databases

1. What is the main difference between SQL and NoSQL databases?

SQL databases are relational, using a structured query language for managing structured data with a predefined schema in tables. NoSQL databases are non-relational, offering a flexible approach for handling unstructured or dynamic data without a fixed schema, often in formats like documents or JSON.

2. Why would someone prefer using a NoSQL database over an SQL database?

NoSQL databases are preferred for their flexibility and scalability, especially suitable for applications with large, unstructured data sets or rapidly changing data structures. They allow for quicker and easier data storage and access without the need for a predefined schema, facilitating faster development cycles.

3. Can SQL databases handle the same types of data as NoSQL databases?

SQL databases are designed for structured data and are highly effective in managing complex queries and transactions with relational data. While they can handle structured data efficiently, they are not as flexible as NoSQL databases in dealing with unstructured or semi-structured data due to their fixed schema requirements.

4. How do SQL and NoSQL databases scale differently?

SQL databases scale vertically, meaning they require more powerful hardware to handle increased loads. NoSQL databases scale horizontally, allowing them to distribute data across multiple servers to manage larger volumes of traffic or data, making them better suited for web-scale applications.

5. What are some examples of SQL and NoSQL database systems?

Examples of SQL database systems include MySQL, PostgreSQL, Oracle, and Microsoft SQL Server, known for their robust transactional support and complex query capabilities. NoSQL database examples include MongoDB, Cassandra, Redis, and Amazon DynamoDB, favored for their scalability and flexibility with unstructured data.

Cloud Integration

SQL vs NoSQL:
5 Critical Differences