I’m sorry. For some reason we’re completely talking past each other… Your harddisk/ssd/usb-stick is a document based database afaik. You store data in form of files/documents on your HDD. It’s a bit like a library, yes. Those documents are organzed a certain way. In folders… maybe on shelves or whatever the digital equivalent is… The important parts of a wiki (the articles) are organized exactly the same way. That’s why DokuWiki manages to pull it off without a relational database. It really doesn’t matter for something like an encyclopedia or knowledge database. Can be articles in a books sitting on shelves in some building. Or digital files on a server, organized by a very similar hierarchy / topics.