I appreciate the effort - but this document is full of misunderstanding. Page faults are a memory management event triggered by virtual memory misses of the Operating System. That is completely separate from how to find a piece of data with an index. Should probably take down the article and do a complete rewrite.
I'm sorry. I might just have skipped things to keep it simpler and not digress into details, but how is it different from finding data with an index?
Search the tree (or whatever data structure) and serve the data. Would you mind telling where did I go wrong exactly?
I don't even know where to start. At the 10,000 foot level, a description of a page fault might sound like an index miss, but the similarity ends there. Data access typically doesn't work at the page level at all - pages only move if the underlying virtual memory system doesn't have a requested address - so it is almost a coincidence if page faults occur at the operating system level when data isn't being found by higher level applications. They are two different systems. I realize that my description is very poor - but these are two complex systems which are being conflated. I don't know of any easy way to describe them both.