Reputation: 1219
An index is an on-disk structure.
I couldn't find anything understandable.
For example, I found this Is it like a file system?
Upvotes: 0
Views: 358
Reputation: 39329
It just means that the index is physically stored on disk, as opposed to "only exists in-memory".
Your link is not related at all.
Upvotes: 1