Question: How does PostgreSQL compare to NoSQL databases in terms of performance?


Performance comparison between PostgreSQL and NoSQL databases can be complex, as it largely depends on the specific use cases, data models, and scalability requirements. Here's a detailed analysis:

Performance in Structured Data Handling

PostgreSQL is a relational database that excels in handling structured data with complex queries. It uses SQL for querying, which is powerful for data manipulation and retrieval. PostgreSQL provides robust transaction support, ensuring ACID (Atomicity, Consistency, Isolation, Durability) properties, which is crucial for applications requiring high data integrity.

SELECT * FROM orders WHERE customer_id = 123;

This SQL query demonstrates PostgreSQL’s ability to quickly retrieve data using a primary key index.

Performance in Scalability and Flexibility

NoSQL databases, such as MongoDB, Cassandra, or Redis, often provide better performance at scale, particularly with unstructured or semi-structured data. They are designed to expand horizontally, meaning you can add more servers easily to handle increased load. This is beneficial for applications with very large datasets or high write loads.

For example, inserting data into MongoDB can be performed rapidly without worrying much about transactional safety, schema conflicts, or complex joins:

db.orders.insertOne({ customer_id: "123", amount: 200, status: "shipped" });

Query Performance

PostgreSQL has powerful indexing options and can efficiently execute complex SQL queries involving multiple tables and conditions. However, it might perform slower under heavy write loads compared to some NoSQL systems optimized for high throughput of write operations.

Use Case Fit

  • eCommerce platforms, financial systems, where complex transactions and reporting are critical, often favor PostgreSQL.
  • Real-time analytics, IoT applications, and scenarios with high write loads or the need for rapid scaling might opt for NoSQL solutions.


Choosing between PostgreSQL and NoSQL should be based on specific project requirements. For transaction-heavy applications where complex queries are common, PostgreSQL is often superior. For applications needing horizontal scalability and flexible schema, NoSQL might offer better performance.

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