Database services
I provide and use two primary RDBMS services, MySQL and PostgreSQL. Between these two and sqlite, I have been able to do anything I have yet needed. I am aware of some of their advantages and limitations and like other tools, I try to use them appropriately.
If you want me to host a database for you, please let me know what you're planning to use it for and how much. I'll want to know estimates of number of concurrent connections, total size, reads/writes per second, etc. so that I can be confident your usage will not adversely impact other usage.