24.05.11 21:48, Greg Smith ÐÐÐÐÑÐÐ(ÐÐ):
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 -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
