Supabase Deep Dive
Supabase positions itself as an open-source Firebase alternative, but with a crucial difference: it's built on PostgreSQL, giving you the full power of a relational database with the convenience of a managed backend service.
The PostgreSQL Foundation
While Firebase uses a NoSQL document model, Supabase embraces SQL. This means you get proper relationships between tables, complex queries with joins, and the entire PostgreSQL ecosystem of extensions and tools. If you already know SQL, you'll feel right at home.
This choice has significant implications. You can write sophisticated queries that would be awkward or impossible in document databases. You can enforce data integrity with foreign keys. And if you ever need to migrate away, your data lives in a standard PostgreSQL database.
Core Services
Supabase bundles several services that work together seamlessly:
Database provides full PostgreSQL access. You can use the dashboard, connect with any PostgreSQL client, or use their JavaScript SDK. Row-level security policies let you control access directly in the database.
Authentication supports email/password, magic links, and social providers like Google and GitHub. Auth integrates tightly with database security policies.
Storage offers S3-compatible file storage with the same security model as your database. Upload user avatars, documents, or any files your application needs.
Edge Functions run Deno-based serverless functions at the edge. Use them for webhooks, custom API endpoints, or server-side logic.
Realtime broadcasts database changes to connected clients. When a row changes, subscribed clients receive updates instantly.
Working With Supabase
import { createClient } from '@supabase/supabase-js';
const supabase = createClient(url, key);
// Query with joins - SQL power through the SDK
const { data, error } = await supabase
.from('users')
.select(`
id,
name,
orders (
id,
total,
items (*)
)
`)
.eq('status', 'active')
.order('created_at', { ascending: false });
// Real-time subscription
supabase
.channel('messages')
.on('postgres_changes',
{ event: 'INSERT', schema: 'public', table: 'messages' },
(payload) => console.log('New message:', payload.new))
.subscribe();
Notice how the select query fetches related data in a single call. This nested selection translates to SQL joins behind the scenes.
Open Source Advantage
Because Supabase is open source, you can self-host if needed. This reduces vendor lock-in concerns and lets you inspect exactly how everything works. Many teams start with Supabase's hosted service, knowing they have an exit path if requirements change.