24.05.11 21:48, Greg Smith написав(ла):
>
> Bitmap heap scan: Here, the exact list of blocks to fetch is known in
> advance, they're random, and it's quite possible for the kernel to
> schedule them more efficiently than serial access of them can do. This
> was added as the effective_io_concurrency feature (it's the only thing
> that feature impacts), which so far is only proven to work on Linux.
> Any OS implementing the POSIX API used will also get this however;
> FreeBSD was the next likely candidate that might benefit when I last
> looked around.
FreeBSD unfortunately do not have the support :(
It has AIO, but does not have the call needed to enable this settings.
Best regards, Vitalii Tymchyshyn