In the days of yore, everyone eschewed mmap because it required platform specific tuning. Then everyone switched to one platform and continued to eschew mmap be

In the days of yore, everyone eschewed mmap because it required platform specific tuning. Then everyone switched to one platform and continued to eschew mmap because they didn't want to read the docs. Sure, you can manifest destiny and write it all yourself, and many do, but if you learn how to make mmap really fly, then you can do that again and again without having to even so much as smell a DBMS. The Linux kernel defaults are pretty horrendous for anything resembling high performance hardware, let alone disks that act like memory, but it can most comfortably accommodate all of those things handedly if you just configure the damn thing properly.