I am trying to sharpen my understanding of Postgres. As I understand,
Postgres does not write directly to disk blocks. It uses the file system
provided by the OS:
https://dba.stackexchange.com/questions/80036/is-there-a-way-to-store-a-postgresql-database-directly-on-a-block-device-not-fi
My question: How can it then store a B Tree on disk? I would think storing
a B Tree requires storing disk offset addresses and so on (for a node to
navigate to another etc.). For this, one would need to write directly to
the disk using low-level disk access functions and not use file system API.
