[brute]

> If they were stored directly as text files it would be slow to query them, it would be very hard to make it work on mobile (and even slower), and you wouldn't be able to easily create relations between notes and tags, notes and notebooks, resource links, etc.

Zim uses plain text files and folders. You can have images, tags, link to other notes, links to the filesystem...

Maybe I am not using it with enough files for it to be a problem, but I cant say that it is slow.

[gh02t]

I think Zim uses a two level approach, storing text files but also keeping an index database for doing full text search.