Does Youtube2mp3.net save all YouTube video files in a database?

Some conversions are very fast. Are mp3 files saved in a database?

Absolutely not!
Youtube2mp3.net does not save YouTube files except for the time required for conversion.
Once converted to mp3 format, all files are deleted.

It would be technically unthinkable to keep a backup of all YouTube files. All conversion requests are processed in real time using the Youtube2mp3.net server network.

Youtube2mp3.net uses various servers in parallel to download and convert video files in real time.