The Difference Between SQL and NoSQL. Why Should I Use Both?

Learning the difference between SQL and NoSQL databases can guide you in choosing the best tools for your project. Each type of database has its benefits but using both SQL and NoSQL can have even greater benefits.

Learn the 4 big differences between SQL and NoSQL as well as instances where you might consider using both to power your technology for the best customer experience and software use.

4 Main Differences Between SQL and NoSQL

At their very core, SQL and NoSQL databases are different. That’s because SQL databases are relational databases, while NoSQL is non-relational. But the difference in architecture translates into 4 main differences between these types of databases.

1. Schemas and Query Languages

SQL databases are characterized by their structured query functions. These databases have a predefined schema that makes data manipulation simple. The ability to complete complex query functions is one reason why SQL is still popular despite its challenges in expanding capacity vertically. 

However, SQL is also somewhat restrictive in that you must decide your schemas and data structure at the onset of a project. You cannot work with your data until you’ve defined it. And all data must then conform to this framework. Working in SQL databases means doing a great deal of pre-work and realizing that changing your data structure could mean disruptions to your application or entire technology system.

In contrast, NoSQL databases are unstructured and you can store your data in a variety of ways, such as column, document, graph, or key-value store. Flexibility in storing data leaves room for creating documents and defining their structure later or allowing each document to have its own structure. Syntaxes can vary from one database to another and you can add fields to your NoSQL database as you go.

2. Database Scalability

SQL databases are challenging to scale. They only scale vertically, which means you have to increase the capacity or load on a server. You’ll need to add more SSD, CPU, or RAM to scale your application.

In contrast, NoSQL databases scale horizontally through a process called sharding. That means that you can add new servers to your NoSQL database. That’s one reason why developers choose NoSQL over SQL is that they can scale as needed and deal with frequently changing data sets.

Some industry experts compare the scaling of SQL to adding more floors to a building. You have to build upward to get more space. In contrast, expanding NoSQL databases is more like adding new buildings to a neighborhood to acquire more space.

3. Data Structure

SQL databases use a table structure. In contrast, NoSQL databases can be document, graph, column, or key-value based.

The added flexibility NoSQL offers is yet another reason why developers have started to prefer working with NoSQL over SQL. 

4. Consistency

SQL databases are well known for their consistency. ACID compliance was once only available in SQL databases. Today, some NoSQL databases like BangDB are ACID-compliant to offer a transactional database. 

While historically NoSQL provides less consistency, this is now more about choosing the right database for the job. Understanding what you need your database to do should be the first step in evaluating the best database for you. If you start there, you should have no trouble finding a NoSQL database that will be consistent to meet your needs.

Pros and Cons of SQL Databases

SQL databases were the only database option for many years and served developer and data scientist needs well. But with the dawn of NoSQL, we’ve also started to recognize its weaknesses. Here are the pros and cons of SQL databases.

Pros

• Flexible query capabilities to support diverse workloads
• Reduced data storage footprint that maximizes database performance
• Familiar language and infrastructure developers know including ACID compliance and properties that developers are familiar with

Cons

• Challenging to scale as needs change and grow
• Opens up your application to a single point of failure since the database is not distributed across various servers
• Data models are rigid and require a pre-defined schema before starting a project

Pros and Cons of NoSQL Databases

While NoSQL is the new technology on the scene and meets the needs of big data, it still has its limitations. Learn about the pros and cons of NoSQL databases before deciding on the best technology for your application.

Pros

• Scalable horizontally and provides excellent availability
• Data models are flexible, allowing you to capture all data your company produces and allows you to adjust data models as needed
• Allows for unstructured data so that you don’t miss out on any data that your company produces so you can analyze and understand everything
• Is high performing to offer your application speed and performance

Cons

• ACID compliance is not available in all NoSQL databases
• Distributing your data can be helpful, but it can also present some challenges and require expertise you may or may not have in-house 

When to Use SQL

Although NoSQL databases have risen in popularity over the last decade, there are still many use cases for SQL databases. Here’s a look at some instances where you might still consider a SQL database.

• To build custom dashboards
• When you need to use joins to execute complex queries
• When you prefer to work with SQL code or your team is only familiar with SQL
• You need to analyze behavioral data or custom session data
• You need ACID compliance

When to Use NoSQL

NoSQL databases are great for transmitting large volumes of data. Here’s a look at when you should use NoSQL.

• You’re dealing with a large volume of data that is unstructured, semi-structured, or a mix of structured, unstructured and semi-structured
• When you don’t need ACID compliance (or select your NoSQL database carefully to find a transactional option)
• A traditional relational model does not meet your needs
• Your data requires a flexible schema
• You need to log data from different sources
• The application does not require constraints or logic
• You need a way to store temporary data, such as a wish list or shopping cart

When You Can Benefit from Both SQL and NoSQL

In some instances, you can use SQL and NoSQL together to gain the benefits of each. Additionally, some NoSQL databases allow for SQL-like queries to allow your development team to work in the language that is familiar to you. 

BangDB uses a Command Line Interface (CLI) to help developers interact with the database in an easy, efficient manner. You can complete nearly any task using the CLI and it accepts SQL-like language. For graph-related queries, BangDB also supports Cypher syntax. 

Adding NoSQL to an existing database can add capacity to a SQL database-based application or allow you to store additional data you aren’t currently logging. You can increase your server storage by adding a NoSQL database without having to remove your SQL database. 

BangDB helps bridge the gap between SQL and NoSQL databases to offer the benefits of each so you can get the most out of your application. Download BangDB now to see the flexibility and modern infrastructure it provides.

Further Reading:

• The Evolution of Databases from SQL to NoSQL
• Does NoSQL Mean Cloud? Best NoSQL Cloud Database Services in 2021
• Best NoSQL Databases for IoT Applications: Commercial and Open Source