I can understand these folks struggling with what mmap is actually doing. But this isn't a new discussion about the qualities of MMAP versus file based IO etc.

I can understand these folks struggling with what mmap is actually doing. But this isn't a new discussion about the qualities of MMAP versus file based IO etc. Although, many of the comments stated are quite wrong. Related Work on this problem: 1. https://www.mongodb.com/blog/post/getting-storage-engines-ready-fast-storage-devices https://www.mongodb.com/blog/post/getting-storage-engines-re... - talks about developments on MongoDB's backend to use mmap. 2. https://www.pdl.cmu.edu/PDL-FTP/Database/p13-crotty.pdf https://www.pdl.cmu.edu/PDL-FTP/Database/p13-crotty.pdf - Talks about some of the cons of mmap, some I think are not as prevalent due to the existence of low latency, high throughput storage devices. 3. https://www.cs.cit.tum.de/fileadmin/w00cfj/dis/_my_direct_uploads/vmcache.pdf https://www.cs.cit.tum.de/fileadmin/w00cfj/dis/_my_direct_up... - less relevant but related.