PostgreSQL

PostgreSQL (often called Postgres) is a powerful, SQL relational database system known for its reliability, feature richness, and standards compliance. It’s widely used in Web Development and enterprise-level applications where data integrity, complex queries, and scalability are essential.

Website: https://www.postgresql.org/

Unlike NoSQL databases like MongoDB, PostgreSQL organizes data in tables and rows with a well-defined schema and supports ACID transactions, ensuring consistency and reliability. It integrates seamlessly with Node.js, Express.js, and ORMs like Prisma or Sequelize.

Features

• ACID Compliance: Ensures data integrity through atomicity, consistency, isolation, and durability.
• Advanced Querying: Powerful SQL support with complex joins, subqueries, and window functions.
• Data Types: Supports a wide range including JSONB, arrays, UUIDs, and custom types.
• Extensions: Highly extensible with modules like PostGIS for geospatial data or pg_trgm for text search.
• Performance Optimization: Indexes, query planner, and caching improve query efficiency.
• Security: Robust authentication, SSL, and role-based access control.

Usage Example

Basic Table

CREATE TABLE users (
  id SERIAL PRIMARY KEY,
  name VARCHAR(100),
  email VARCHAR(150) UNIQUE NOT NULL,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

Connecting with Node.js (using pg)

import pkg from 'pg';
const { Pool } = pkg;
 
const pool = new Pool({
  connectionString: process.env.DATABASE_URL,
});
 
const result = await pool.query(
  'INSERT INTO users (name, email) VALUES ($1, $2) RETURNING *',
  ['Ashwin', 'ashwin@example.com']
);
 
console.log(result.rows[0]);

Advantages

• Strong data integrity and reliability with full ACID support
• Advanced SQL querying and indexing capabilities
• Excellent for analytical and transactional workloads
• JSONB support combines relational and NoSQL-style flexibility
• Widely supported across cloud platforms and ORMs

Limitations

• More complex to scale horizontally compared to MongoDB
• Requires predefined schemas, making early development less flexible
• Slightly higher setup and maintenance overhead

Purpose

PostgreSQL is ideal for production-grade applications that demand data consistency, complex relationships, and strong transactional guarantees.