# Database Selection SQL Vs Nosql > Guidance and best practices for database selection (sql vs nosql). Use when this capability is needed. - Skill: `tomevault-io/database-selection-sql-vs-nosql` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/database-selection-sql-vs-nosql` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/database-selection-sql-vs-nosql/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Data & Analytics - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/database-selection-sql-vs-nosql --- # Database Selection (SQL vs NoSQL) ## SQL (Relational) - **Examples**: PostgreSQL, MySQL. - **Use Case**: Structured data, complex relationships, transactions (ACID), reporting. - **Schema**: Rigid, requires migrations. ## NoSQL (Non-Relational) - **Examples**: MongoDB (Document), Redis (Key-Value), Cassandra (Wide-Column). - **Use Case**: Unstructured data, high write throughput, horizontal scaling, flexible schema. - **Schema**: Flexible/Schema-less. ## Selection - Choose **SQL** by default for most business applications. - Choose **NoSQL** for specific needs like caching (Redis), massive logs, or rapidly changing data structures. --- > Source: [jyjeanne/ai-setup-forge](https://github.com/jyjeanne/ai-setup-forge) — distributed by [TomeVault](https://tomevault.io).