I wonder if ram fs would perform exact the same as sqlite in memory.
The article speculates that the overhead of calling `fopen` for each file and subsequently reading it is more expensive than reading from an already opened database file.
But as for how expensive `fopen` is really depends many factors.
I would believe ramfs would be slower, as there will be additional system calls needed.
Filesystems can be built in memory (ramdisks) too, but comparing sqlite in memory to files on disk would be pretty silly. For any serious and fair comparison, in sqlite still means on disk.