Choosing Between Relational and NoSQL Databases: A Developer's Guide published 9/3/2023 | 3 min read

In the expanding landscape of web development, picking the right database technology is a critical decision. The choice between Relational (SQL) and non-Relational (NoSQL) databases often presents developers with a dilemma. In this post, we explore the significant differences, strengths, and drawbacks of these database types to help you make an informed choice.

Please note that the decision should always depend on your project requirements.

What is a Relational (SQL) Database?

Relational databases, also known as SQL databases, derive their name from the way they organize data into structured tables. These tables maintain "relations" amongst themselves via common data shared across different tables.

Here's a simple example of a relational database table:

  
CREATE TABLE Customers (
  ID INT UNIQUE, 
  Name VARCHAR(255), 
  Email VARCHAR(255), 
  Phone VARCHAR(15), 
  BirthDate Date,
  PRIMARY KEY (ID)
);

SQL databases are typically best suited for applications that require complex queries and a strict consistency of data. They excel in handling structured data and support ACID transactions (Atomic, Consistency, Isolation, Durability).

The Pros and Cons of SQL Databases

Advantages:

• Strong data consistency
• High data safety
• Support for complex queries
• Wide tech support and community

Drawbacks:

• Limited horizontal scalability
• Reduced flexibility with structured data
• Inefficient to handle high-velocity data

What is a NoSQL Database?

Contrary to SQL databases, NoSQL databases do not rely on structured tables with predefined schemas. Instead, they store data in varied ways - key-value pairs, wide-column stores, graph databases, or document-oriented databases.

Here's an example of a document in a NoSQL database (MongoDB):

  
{
  "_id": ObjectId("551582c2f421f0123d541a7b"),
  "firstName": "John",
  "lastName": "Doe",
  "email": "john.doe@example.com",
  "phone": "+1234567890",
  "birthDate": "1995-03-01"
}

NoSQL databases are more flexible and provide high performance with high-volume and diversified data. They are well-suited for modern web applications dealing with big data, real-time web services, and IoT devices.

The Pros and Cons of NoSQL Databases

Advantages:

• High versatility with diverse data types
• Excellent horizontal scalability
• Superior performance

Drawbacks:

• Inconsistent data models
• Limited support for complex queries
• Most NoSQL systems don't support ACID transactions

Choosing Between SQL and NoSQL

The biggest factor in choosing between SQL and NoSQL should be the nature of your data and the expected use-cases. If you're dealing with high-volume, diversified data or require advanced horizontal scaling, NoSQL institutions may be your ideal choice. Conversely, if your project requires complex transactions or stronger data consistency, it's probably best to stick with a SQL database.

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