Tomas Vondra <tomas.von...@2ndquadrant.com> writes: > Yeah, I think the question is what are the expected benefits of using > raw devices. It might be an interesting exercise / experiment, but my > understanding is that most of the benefits can be achieved by using file > systems but with direct I/O and async I/O, which would allow us to > continue reusing the existing filesystem code with much less disruption > to our code base.
There's another very large problem with using raw devices: on pretty much every platform, you don't get to do that without running as root. It is not easy to express how hard a sell it would be to even consider allowing Postgres to run as root. Between the security issues, and the generally poor return-on-investment we'd get from reinventing our own filesystem and I/O scheduler, I just don't see this sort of thing ever going forward. Direct and/or async I/O seems a lot more plausible. regards, tom lane