Database Designer

This handles schema normalization analysis, index optimization based on query patterns, and migration script generation with rollback procedures for PostgreSQL and MySQL. You get Mermaid ERDs, composite index recommendations ordered by selectivity, and expand-contract patterns for zero-downtime migrations on large tables. The workflows are solid: feed it DDL or JSON schemas, run the analyzers, get actionable output. It catches the usual problems like missing foreign keys and over-indexing, plus generates validation queries for every migration step. The scope is clear about what it won't do (no live profiling, no NoSQL-specific design), which saves time. If you're designing schemas or planning migrations without locking production tables, this covers the mechanics well.

skills.sh installs: 170
GitHub stars: 1.1K
last updated: Aug 21, 2026

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Install

$ npx -y skills add borghei/claude-skills --skill database-designer --agent claude-code

Installs into .claude/skills of the current project.

Files

Database Designer

The agent analyses an existing relational schema for normalization, constraint, naming and type problems, recommends indexes for the queries that actually run, and generates forward and rollback migrations between two schema versions. To design a new schema from product requirements (ERDs, RLS, ORM models), use engineering/database-schema-designer instead.

When to Use

Reviewing a schema (DDL or JSON) before or after a change.
Choosing or pruning indexes for a known set of queries.
Turning a schema diff into a migration with rollback and validation queries, optionally zero-downtime (expand-contract).
Choosing between database engines for a workload (reference only).

Clarify First

Before designing or migrating, settle the inputs below. When one is missing or vague and would change the result, ask about it; when it wouldn't, use a sensible default and say which one you used.

SKILL.md on GitHub