Blog | Khaled Dev

TL;DR

Summary

Why PostgreSQL Over MySQL or SQLite?

PostgreSQL is the most advanced open-source relational database. It supports JSON, full-text search, geospatial queries, window functions, and ACID compliance. Used by Instagram, Spotify, Notion, and thousands more.

PostgreSQL

✅ JSONB native support
✅ Full-text search built-in
✅ Better ACID compliance
✅ Window functions & CTEs

MySQL

✅ Slightly faster reads (simple)
✅ More shared hosting support
❌ Less feature-rich
❌ Oracle ownership concerns

Essential Queries You Must Know

PostgreSQL — Essential SQL

-- Create a table
CREATE TABLE projects (
    id SERIAL PRIMARY KEY,
    title VARCHAR(200) NOT NULL,
    tags TEXT[],
    metadata JSONB,
    created_at TIMESTAMP DEFAULT NOW()
);

-- Insert
INSERT INTO projects (title, tags, metadata)
VALUES ('Hesabi', ARRAY['nextjs','postgres'], '{"live": true}');

-- Query with JSON
SELECT title FROM projects
WHERE metadata->>'live' = 'true';

-- Array contains
SELECT * FROM projects
WHERE 'nextjs' = ANY(tags);

-- Full-text search
SELECT * FROM projects
WHERE to_tsvector('english', title) @@ to_tsquery('accounting');

Indexing — The Biggest Performance Win

Without indexes, every query scans the entire table. With the right index, queries go from seconds to milliseconds. Rule: add an index to any column you regularly filter or sort by.

Indexes — When and How

-- Basic index
CREATE INDEX idx_projects_title ON projects(title);

-- Partial index (only index active records)
CREATE INDEX idx_active_users ON users(email)
WHERE is_active = true;

-- GIN index for JSONB and arrays
CREATE INDEX idx_projects_tags ON projects USING GIN(tags);
CREATE INDEX idx_projects_meta ON projects USING GIN(metadata);

-- Check slow queries
EXPLAIN ANALYZE SELECT * FROM projects WHERE title = 'Hesabi';

Django's ORM works perfectly with PostgreSQL. Use ArrayField, JSONField, and SearchVector for full-text search — all native Django features powered by PostgreSQL.

Key Takeaways

Use PostgreSQL for any serious project. Start with simple schemas, add indexes when queries slow down, and explore JSON features when you need flexibility. It will grow with you from side project to production scale.

PostgreSQL SQL Base de données Django Backend Tunisie

Article

Why PostgreSQL Over MySQL or SQLite?

Essential Queries You Must Know

Indexing — The Biggest Performance Win

Key Takeaways