On Tue, Oct 19, 2010 at 8:25 AM, Merlin Moncure <mmoncure@xxxxxxxxx> wrote: > On Tue, Oct 19, 2010 at 9:10 AM, Jon Nelson <jnelson+pgsql@xxxxxxxxxxx> wrote: >> No replies? >> >> This is another situation where using pread would have saved a lot of >> time and sped things up a bit, but failing that, keeping track of the >> file position ourselves and only lseek'ing when necessary would also >> help. Postgresql was spending 37% of it's time in redundant lseek! > > 37% of cpu time? ÂIs that according to strace -T? how did you measure it? Per the original post, it (redundant lseek system calls) accounted for 37% of the time spent in the kernel. strace -f -p <pid> -c -- Jon -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
