QuestDB is open source and will remain so forever. You will be able to scale with it. Our commercial product, Pulsar, uses QuestDB as a library and will offer enterprise integration and monitoring features, which are typically required for massive enterprise deployment.

To answer your question, it will depend how big of a scale we are looking into. If you are a large company running questdb throughout the organization and need a specific feature set to do so, you will probably be looking to get our paid offering.