Agent-Skills.md

Agent Skills: Databases Skill

Work with MongoDB (document database, BSON documents, aggregation pipelines, Atlas cloud) and PostgreSQL (relational database, SQL queries, psql CLI, pgAdmin). Use when designing database schemas, writing queries and aggregations, optimizing indexes for performance, performing database migrations, configuring replication and sharding, implementing backup and restore strategies, managing database users and permissions, analyzing query performance, or administering production databases.

UncategorizedID: binjuhor/shadcn-lar/databases

Repository

binjuhor/shadcn-lar
binjuhor
6019

Install this agent skill to your local

pnpm dlx add-skill https://github.com/binjuhor/shadcn-lar/tree/HEAD/.claude/skills/databases

Skill Files

Browse the full folder contents for databases.

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.claude/skills/databases/SKILL.md

Skill Metadata

Name
ck:databases
Description
Design schemas, write queries for MongoDB and PostgreSQL. Use for database design, SQL/NoSQL queries, aggregation pipelines, indexes, migrations, replication, performance optimization, psql CLI.

Databases Skill

Unified guide for working with MongoDB (document-oriented) and PostgreSQL (relational) databases. Choose the right database for your use case and master both systems.

When to Use This Skill

Use when:

  • Designing database schemas and data models
  • Writing queries (SQL or MongoDB query language)
  • Building aggregation pipelines or complex joins
  • Optimizing indexes and query performance
  • Implementing database migrations
  • Setting up replication, sharding, or clustering
  • Configuring backups and disaster recovery
  • Managing database users and permissions
  • Analyzing slow queries and performance issues
  • Administering production database deployments

Reference Navigation

Database Design

  • db-design.md - Activate when user requests: Database/table design for transactional (OLTP), analytics (OLAP), create or extend schema, design fact/dimension tables, analyze/review CSV/JSON/SQL files to create tables, or need advice on data storage structure.

MongoDB References

PostgreSQL References

Python Utilities

Database utility scripts in scripts/:

  • db_migrate.py - Generate and apply migrations for both databases (MongoDB and PostgreSQL)
  • db_backup.py - Backup and restore MongoDB and PostgreSQL
  • db_performance_check.py - Analyze slow queries and recommend indexes
# Generate migration
python scripts/db_migrate.py --db mongodb --generate "add_user_index"

# Run backup
python scripts/db_backup.py --db postgres --output /backups/

# Check performance
python scripts/db_performance_check.py --db mongodb --threshold 100ms

Best Practices

MongoDB:

  • Use embedded documents for 1-to-few relationships
  • Reference documents for 1-to-many or many-to-many
  • Index frequently queried fields
  • Use aggregation pipeline for complex transformations
  • Enable authentication and TLS in production
  • Use Atlas for managed hosting

PostgreSQL:

  • Normalize schema to 3NF, denormalize for performance
  • Use foreign keys for referential integrity
  • Index foreign keys and frequently filtered columns
  • Use EXPLAIN ANALYZE to optimize queries
  • Regular VACUUM and ANALYZE maintenance
  • Connection pooling (pgBouncer) for web apps

Resources

  • MongoDB: https://www.mongodb.com/docs/
  • PostgreSQL: https://www.postgresql.org/docs/
  • MongoDB University: https://learn.mongodb.com/
  • PostgreSQL Tutorial: https://www.postgresqltutorial.com/