On Wed, Aug 7, 2013 at 11:21 AM, Thom Brown <t...@linux.com> wrote: > Hi all, > > I recently tried a simple benchmark to see how far 9.4 had come since > 8.4, but I discovered that I couldn't get 9.4 to even touch 8.4 for > performance. After checking 9.2 and 9.3 (as per Kevin Grittner's > suggestion), I found that those were fine, so the issue must be in > 9.4devel. I used identical configurations for each test, and used > 9.1's pgbench to ensure changes in pgbench didn't affect the outcome. > The common config changes were:
... > 8.4: 812.482108 > 9.4 HEAD: 355.397658 > 9.4 e5592c (9th July): 356.485625 > 9.4 537227 (7th July): 365.992518 > 9.4 9b2543 (7th July): 362.587339 > 9.4 269e78 (5th July): 359.439143 > 9.4 8800d8 (5th July): 821.933082 > 9.4 568d41 (2nd July): 822.991160 > > 269e78 was the commit immediately after 8800d8, so it appears that > introduced the regression. > > "Use posix_fallocate() for new WAL files, where available." > > Ironically, that was intended to be a performance improvement. Would it be possible for you to download, compile, and run the test program as described and located in this email: http://www.postgresql.org/message-id/cakuk5j1acml-1cgbhnrzed-vh4og+8hkmfhy2eca-8jbj-6...@mail.gmail.com I also wonder if there is a problem with the 3.8.0 kernel specifically. -- Jon -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
