database_skill

Overview

This skill helps non-technical founders choose databases, design multi-tenant schemas, set up Supabase or equivalent, write queries, and fix data issues. It focuses on simple, secure patterns for SaaS: organization-based multi-tenancy, Row Level Security, migrations, and practical performance tips. The guidance favors pragmatic defaults so you can ship quickly and safely.

How this skill works

I inspect your product’s core objects and recommend a minimal schema that maps users to organizations and ties all customer data to an org_id. I generate SQL for tables, indexes, RLS policies, and migrations, and point out where to add soft deletes, audit logs, and common constraints. I also review queries and offer simple performance improvements and testing steps for migrations and RLS.

When to use it

• You’re building a SaaS and need a secure multi-tenant schema.
• You need a migration written for Supabase/Postgres or RLS policies added.
• You must fix data leaks or enforce org-level isolation.
• You want simple performance fixes for slow queries or missing indexes.
• You’re deciding whether to use Supabase/Postgres or another hosted DB.

Best practices

• Use the database provided by your hosting platform (Supabase/Postgres by default).
• Design schema with org_id on every customer table and index it.
• Enable Row Level Security on all customer-facing tables and write SELECT/INSERT/UPDATE policies tied to memberships.
• Never change production schema directly—use versioned migrations and test on a branch DB first.
• Start simple: avoid Redis/Elasticsearch/data warehouses until you have measurable needs.

Example use cases

• Create users, organizations, and memberships tables with proper constraints and timestamps.
• Add a core business table (projects, invoices) linked to org_id with indexes and RLS policies.
• Write a Supabase migration to add a status column plus updated RLS policy adjustments.
• Audit and fix an RLS misconfiguration that allows cross-org reads.
• Optimize a slow query by adding indexes and switching to cursor-based pagination.