---
name: database-design
description: "Database design principles and decision-making. Schema design, indexing strategy, ORM selection, serverless databases."
risk: safe
source: community
date_added: "2026-02-27"
---

# Database Design

> **Learn to THINK, not copy SQL patterns.**

## 🎯 Selective Reading Rule

**Read ONLY files relevant to the request!** Check the content map, find what you need.

| File | Description | When to Read |
|------|-------------|--------------|
| `database-selection.md` | PostgreSQL vs Neon vs Turso vs SQLite | Choosing database |
| `orm-selection.md` | Drizzle vs Prisma vs Kysely | Choosing ORM |
| `schema-design.md` | Normalization, PKs, relationships | Designing schema |
| `indexing.md` | Index types, composite indexes | Performance tuning |
| `optimization.md` | N+1, EXPLAIN ANALYZE | Query optimization |
| `migrations.md` | Safe migrations, serverless DBs | Schema changes |

---

## ⚠️ Core Principle

- ASK user for database preferences when unclear
- Choose database/ORM based on CONTEXT
- Don't default to PostgreSQL for everything

---

## Decision Checklist

Before designing schema:

- [ ] Asked user about database preference?
- [ ] Chosen database for THIS context?
- [ ] Considered deployment environment?
- [ ] Planned index strategy?
- [ ] Defined relationship types?

---

## Anti-Patterns

❌ Default to PostgreSQL for simple apps (SQLite may suffice)
❌ Skip indexing
❌ Use SELECT * in production
❌ Store JSON when structured data is better
❌ Ignore N+1 queries

## When to Use
Use when selecting a database model, reviewing schema relationships and indexes, or assessing a proposed schema with the bundled advisory tools.

## Schema helper

`scripts/schema_validator.py` is a read-only heuristic inventory, not a Prisma or Drizzle parser. Missing schemas, unsupported formats and heuristic-only results return nonzero with `passed: false` and `analysis_complete: false`. Use the project-local ORM validator for syntax and type checks; review migration and constraint semantics separately.

## Limitations
- Use this skill only when the task clearly matches the scope described above.
- Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
- Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.


---
Source attribution: vudovn
Original project: https://github.com/vudovn/antigravity-kit
License: MIT + CC-BY-4.0
License information: https://creativecommons.org/licenses/by/4.0/
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2026 Antigravity User

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.


Creative Commons Attribution 4.0 International (CC BY 4.0)

This file clarifies the license for original non-code repository content.

- Original code and tooling remain licensed under the MIT License in `LICENSE`.
- Original documentation and other non-code written content are licensed under
  the Creative Commons Attribution 4.0 International license unless a more
  specific upstream notice says otherwise.
- Third-party attributions, upstream licenses, and exceptions are tracked in
  `docs/sources/sources.md`.

Canonical license URL:
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Review the full license text at the canonical URL before reuse.



# Mega AI Hub resource metadata

Creator / publisher: vudovn
Original project: https://github.com/vudovn/antigravity-kit
Attribution basis: Original project explicitly identified in package addition commit

Fields of work: Data & Analytics, Development & Engineering
Roles: Data Analyst, Data Engineer, Database Administrator
Specialties: Backend, Database, Design, DevOps, Frontend, Testing
Tools: MySQL, PostgreSQL, SQLite
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 83c571590a5ae3a19bd4dfdd7e8d160a9c93457add2800e21adb0a7752d67d0a
Metadata reviewed: 2026-10-27
This metadata supersedes earlier Mega AI Hub catalog attribution. Original instruction and supporting files are preserved.