Ok so before I get bashed: I know it's something huge for one person; I don't care if the end product can actually be used or not.

I need to learn how databases work in order to use them more efficiently, and my way of learning is by doing.

So I want to create my own database system. I am not referring to creating a pseudo-database that would use query to parse files; this would simply be a filesystem interface with a query language. I am talking about the actual structure of a database engine. And since what I have in mind is neither relational nor document-oriented (it's "node-oriented", if that even exists), I would need any resource to be as abstract and high-level as possible.

So how would I go about creating that? What resources/tutorials/books can I read to understand?

The language does not matter in the slightest. Ideally, the code would be pseudo-code to illustrate the concept, not tied to a particular language, but anything would do. I was not able to find anything on the matter on google (since I am so illiterate on the subject, maybe I am just not entering the right search).

If such resources are not available, then I guess something about how to create a client would at least be a step in the right direction.