In modern software projects, the choice of database directly affects the speed, security, scalability, and long-term success of the project. However, the abundance of open-source and commercial database solutions on the market can complicate the decision-making process for developers. In this guide, we comprehensively, technically, and simply compare the 4 most popular databases: MySQL, MariaDB, PostgreSQL, and MongoDB.

General Definitions

Database	Type	Data Model	Open Source	Best Use Case
MySQL	RDBMS	Relational (table-based)	✅	Web applications, WordPress, e-commerce
MariaDB	RDBMS	Relational	✅	Those seeking a MySQL alternative, high performance
PostgreSQL	ORDBMS	Object + Relational	✅	Big data, geographic data, enterprise solutions
MongoDB	NoSQL	Document (JSON-like BSON)	✅	Real-time applications, flexible schema requirements

1. MySQL: Powerful with Prevalence and Community Strength

Advantages:

Most widely used open-source database
Strong integration with systems like PHP, WordPress, Laravel
Comes as default on cPanel servers

Disadvantages:

Managed by Oracle (some versions are commercial)
Performance tuning limitations

Suitable for? SME websites, blogs, small to medium-sized projects

⚙️ 2. MariaDB: MySQL's Free and Fast Alternative

It is the open-source continuation of MySQL. Its developers were created by the founders of MySQL.

Advantages:

Fully compatible with MySQL (DROP-IN REPLACEMENT)
Faster read/write operations
Built-in replication technologies like Galera Cluster

Disadvantages:

Large enterprise support providers are generally focused on MySQL

Suitable for? High traffic sites, large databases, open-source supported systems

3. PostgreSQL: Enterprise Level with Advanced Features

Advantages:

Supports JSON, XML, GIS data types
ACID compliance is very strong
Most stable structure in multiple concurrent write operations
Advanced RDBMS features such as view, trigger, stored procedure

Disadvantages:

Steeper learning curve
Hosting panel support may be limited (e.g., cPanel, Plesk)

Suitable for? Enterprise applications, geographic information systems (GIS), finance, healthcare systems

4. MongoDB: The Flexible Power of the NoSQL World

Advantages:

Schema-less data structure (JSON-like documents)
Superior performance in real-time data
Automatic sharding (data partitioning)
High scalability and flexibility

Disadvantages:

ACID guarantee is limited (better after version 4.0)
Requires a learning process for developers who have learned SQL

Suitable for? Chat applications, IoT systems, large e-commerce catalogs, data streaming systems

Technical Comparison Table

Feature	MySQL	MariaDB	PostgreSQL	MongoDB
Data Structure	Tables	Tables	Tables + Object	Documents (JSON)
ACID Compliance	Yes	Yes	Very strong	Partially (4.0+)
JSON Support	Limited	Limited	Native and strong	Basic structure
Performance (Read)	Medium	Fast	Stable	Very fast
Performance (Write)	Medium	Fast	Good	High
Distributed Structure	Limited	Galera Cluster	Logical Replication	Sharding
Supporting Panels	cPanel, Plesk	cPanel, Plesk	Plesk, Webmin	Usually custom panel

Impacts in Terms of SEO, Web Hosting, and Application Performance

In terms of SEO: Website speed is important. MySQL and MariaDB provide an advantage in terms of SEO because they work integrated with CMSs such as WordPress.
Web Hosting: MySQL/MariaDB is common in shared hosting.
Performance: PostgreSQL and MongoDB offer more stable and powerful performance in systems containing a lot of data.