Utilizing Serverless Databases for Scalable Application Development

Assume the role of a cloud database architect and provide a comprehensive guide on leveraging serverless databases for building scalable and cost-effective applications. Include detailed steps for choosing the right serverless database solution such as AWS Aurora Serverless, Google Cloud Firestore, or Azure Cosmos DB. Address key considerations such as data modeling, schema design, query optimization, performance tuning, and cost management strategies. Provide examples of common use cases and pitfalls to avoid. Discuss integration with services and tools like PostgreSQL, MySQL, and SQLite, and suggest best practices for migrations, security, and troubleshooting. Aim for clarity and completeness in your guidance.