Are cloud based DBaaS providers secure for databases?


this is my first question on this board and I really hope I’m asking everything right. At work I’m in charge of collecting all the customer data for marketing purposes. Until now everything went really smoothly and I’ve had almost no problems at all. But recently my database has been oddly slow. I’m suspecting that it has something to do with the server capacity or something. Anyways, I’ve been doing some thinking and I’ve come to the conclusion that I want to change things up a bit. Maybe a cloud based approach could work better for our needs. There are some providers, like Aiven, who turn open source software into fully fledged databases. Does anyone have any experience with something like that, especially with Aiven? Is that really open source? How secure is such an cloud based provider?