1. Deployment Process: Heroku Postgres offers a simpler deployment process compared to MySQL. With Heroku Postgres, you can easily provision and scale your database by using the Heroku CLI or the Heroku Dashboard. On the other hand, MySQL requires manual installation and configuration on your server, which involves more complexity and potential for errors.

2. Managed Service: Heroku Postgres is a fully managed service, which means that Heroku takes care of the database infrastructure and maintenance tasks like backups, patches, and updates. On the other hand, MySQL requires manual management and administration, making it more time-consuming and requiring technical expertise.

3. PostgreSQL vs. SQL: Heroku Postgres uses the PostgreSQL database, while MySQL uses the SQL database. Although both databases are widely used and offer similar functionality, there are some key differences. PostgreSQL has a more extensive list of advanced features, including support for complex data types, advanced indexing, and more robust transaction support. MySQL, on the other hand, is known for its simplicity and ease of use.

4. Price Structure: Heroku Postgres offers a flexible pricing structure based on usage, allowing you to scale up or down as needed. You pay based on the resources and features you use. MySQL typically requires a more traditional licensing model, where you purchase a certain number of licenses or pay for the software upfront. This can make it less flexible and potentially more expensive, especially for smaller projects.

5. Integration with Heroku Platform: Heroku Postgres is tightly integrated with the Heroku platform, allowing for smooth deployment and management of web applications. It provides seamless integration with other Heroku services, like the Heroku CLI, Heroku Dashboard, and Heroku Pipelines. MySQL, on the other hand, is not specifically designed for Heroku and may require additional configuration and setup.

6. Ecosystem and Community: Both Heroku Postgres and MySQL have vibrant ecosystems and community support. However, MySQL has been around for a longer time and has a larger user base. This means that there are more resources, guides, and community-driven plugins available for MySQL. However, the PostgreSQL community is known for its technical expertise and extensive documentation.

In Summary, Heroku Postgres offers a simpler deployment process, is a fully managed service, uses PostgreSQL database, has a flexible price structure, tightly integrates with the Heroku platform, and has a strong community. MySQL, on the other hand, requires manual setup and management, uses SQL database, has a more traditional pricing model, may require additional configuration on Heroku, and has a larger user base.