Based on what? I did test this and posted the data. The results I
posted showed that posix_fadvise on Linux performed nearly as well on
Linux as async I/O on Solaris on identical hardware.
More importantly it scaled with the number if drives. A 15 drive array
gets about 15x the performance of a 1 drive array if enough read-ahead
is done. Plus an extra boost if the input wasn't already sorted which
presumably reflects the better i/o ordering.
--
greg
On 24 Oct 2008, at 04:29 AM, "Jonah H. Harris"
<[EMAIL PROTECTED]> wrote:
On Thu, Oct 23, 2008 at 8:44 PM, Bruce Momjian <[EMAIL PROTECTED]>
wrote:
True, it is a kludge but if it gives us 95% of the benfit with 10% of
the code, it is a win.
I'd say, optimistically, maybe 30-45% the benefit over a proper
multi-block read using O_DIRECT.
--
Jonah H. Harris, Senior DBA
myYearbook.com
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
