Supabase Support Lab

Hands-on support engineering lab built around a hosted Supabase project. The goal was to reproduce realistic support incidents, collect evidence, diagnose root causes, apply fixes, and validate recovery.

What this lab covers

• Supabase Data API / PostgREST
• PostgreSQL troubleshooting and query performance
• Row Level Security (RLS)
• Supabase Auth and JWT-based access
• Supabase Storage authorization
• Unified Logs / API Gateway correlation
• External PostgreSQL connectivity with psql
• Incident documentation and recovery validation

Incident summary

Incident	Symptom	Root cause	Recovery
INC-001	Data API returned no rows although rows existed	RLS enabled with no matching SELECT policy	Added policy and verified rows returned
INC-002	Login/API authorization failures	Malformed JSON, bad API key input, then invalid credentials	Corrected request, authenticated successfully, validated JWT + authenticated RLS
INC-003	Single-row lookup scanned ~50k rows	Missing index on customer_email	Added B-tree index and verified indexed execution plan
INC-004	Competing lock acquisition	Resource already held by another session	Demonstrated contention and recovery using PostgreSQL advisory locks
INC-005	REST request returned HTTP 404 / PGRST205	Misspelled table/resource in endpoint	Correlated API Gateway log and corrected endpoint to HTTP 200
INC-006	Storage upload denied	No matching storage.objects INSERT policy	Added authenticated bucket-scoped policy and verified HTTP 200 upload
INC-007	External PostgreSQL login failed	Invalid database password	Retried with correct credentials and verified live DB access via Session Pooler

PostgreSQL performance evidence

Before indexing, the lookup on customer_email used a sequential scan and removed 50,003 rows by filter. After adding an index, PostgreSQL used the index path, shared buffer hits dropped from 703 to 4, and the captured execution time was 0.128 ms.

See:

• incidents/INC-003-postgres-performance.md
• evidence/screenshots/INC-003-before-seq-scan.png
• evidence/screenshots/INC-003-after-index.png

Repository structure

supabase-support-lab/
├── README.md
├── SECURITY.md
├── sql/
├── incidents/
├── runbooks/
└── evidence/
    └── screenshots/

Security note

No passwords, JWTs, service-role keys, database passwords, or other secrets should be committed to this repository. Screenshots included here were selected to avoid exposing credentials.

Environment

• Supabase hosted project
• PostgreSQL
• PowerShell / curl
• psql
• Supabase SQL Editor
• Supabase Unified Logs