The buffers article followed an 8KB page from disk into shared memory and back. What it didn't do is name the file. Every page that passes through the buffer pool is block number N of some file under the data directory, and the file has a naming scheme, a size limit, and companion files that share its name. Before the next article reads the inside of a page, this one finds it on disk with ls and od, and shows that the bytes are the same ones. Nothing here needs more than a scratch database and shell access to its...