Supabase Postgres Best Practices

Comprehensive performance optimization guide for Postgres, maintained by Supabase. Contains rules across 8 categories, prioritized by impact to guide automated query optimization and schema design.

This repository (Asymmetric-al/core)

• Auth flows in Next.js without heavy SQL work: docs/ai/skills/nextjs-supabase-auth/SKILL.md
• Broader Supabase product surface (CLI, MCP, Storage, etc.): docs/ai/skills/supabase/SKILL.md
• Migration and seed workflow: supabase/AGENTS.md

When to Apply

Reference these guidelines when:

• Writing SQL queries or designing schemas
• Implementing indexes or query optimization
• Reviewing database performance issues
• Configuring connection pooling or scaling
• Optimizing for Postgres-specific features
• Working with Row-Level Security (RLS)
• Reviewing migrations under supabase/migrations/*.sql

Do not use this skill when:

• The task is only UI/UX and has no data-path impact
• The task is only auth UX with no database/query work (use nextjs-supabase-auth)

Rule Categories by Priority

Priority	Category	Impact	Prefix
1	Query Performance	CRITICAL	query-
2	Connection Management	CRITICAL	conn-
3	Security & RLS	CRITICAL	security-
4	Schema Design	HIGH	schema-
5	Concurrency & Locking	MEDIUM-HIGH	lock-
6	Data Access Patterns	MEDIUM	data-
7	Monitoring & Diagnostics	LOW-MEDIUM	monitor-
8	Advanced Features	LOW	advanced-

Workflow (this repo)

1. Identify the hot path (query latency, lock contention, scan volume, or RLS overhead).
2. Inspect indexing and query-shape problems first (query-*, schema-*).
3. Validate RLS and policy cost for protected tables (security-*).
4. Prefer schema and access-pattern fixes before low-level micro-optimizations.
5. Verify with realistic query plans and app behavior.
6. If behavior changes, update relevant backend docs and migration notes.

How to Use

Read individual rule files for detailed explanations and SQL examples:

references/query-missing-indexes.md
references/query-partial-indexes.md
references/_sections.md

Each rule file contains:

• Brief explanation of why it matters
• Incorrect SQL example with explanation
• Correct SQL example with explanation
• Optional EXPLAIN output or metrics
• Additional context and references
• Supabase-specific notes (when applicable)

Checklist

• Query path reviewed for index/selectivity issues
• RLS policies reviewed for correctness and cost
• Schema/index changes are migration-safe
• No unsafe bypass patterns introduced
• Verification steps documented (query checks or app flow checks)

References

• https://www.postgresql.org/docs/current/
• https://supabase.com/docs
• https://wiki.postgresql.org/wiki/Performance_Optimization
• https://supabase.com/docs/guides/database/overview
• https://supabase.com/docs/guides/auth/row-level-security
• references/upstream.md for vendor refresh steps