On 2016-06-08 23:00:15 -0400, Noah Misch wrote: > On Sun, May 29, 2016 at 01:26:03AM -0400, Noah Misch wrote: > > On Thu, May 12, 2016 at 10:49:06AM -0400, Robert Haas wrote: > > > On Thu, May 12, 2016 at 8:39 AM, Ashutosh Sharma <ashu.coe...@gmail.com> > > > wrote: > > > > Please find the test results for the following set of combinations > > > > taken at > > > > 128 client counts: > > > > > > > > 1) Unpatched master, default *_flush_after : TPS = 10925.882396 > > > > > > > > 2) Unpatched master, *_flush_after=0 : TPS = 18613.343529 > > > > > > > > 3) That line removed with #if 0, default *_flush_after : TPS = > > > > 9856.809278 > > > > > > > > 4) That line removed with #if 0, *_flush_after=0 : TPS = 18158.648023 > > > > > > I'm getting increasingly unhappy about the checkpoint flush control. > > > I saw major regressions on my parallel COPY test, too: > > > > > > http://www.postgresql.org/message-id/ca+tgmoyouqf9cgcpgygngzqhcy-gcckryaqqtdu8kfe4n6h...@mail.gmail.com > > > > > > That was a completely different machine (POWER7 instead of Intel, > > > lousy disks instead of good ones) and a completely different workload. > > > Considering these results, I think there's now plenty of evidence to > > > suggest that this feature is going to be horrible for a large number > > > of users. A 45% regression on pgbench is horrible. (Nobody wants to > > > take even a 1% hit for snapshot too old, right?) Sure, it might not > > > be that way for every user on every Linux system, and I'm sure it > > > performed well on the systems where Andres benchmarked it, or he > > > wouldn't have committed it. But our goal can't be to run well only on > > > the newest hardware with the least-buggy kernel... > > > > [This is a generic notification.] > > > > The above-described topic is currently a PostgreSQL 9.6 open item. Andres, > > since you committed the patch believed to have created it, you own this open > > item. If some other commit is more relevant or if this does not belong as a > > 9.6 open item, please let us know. Otherwise, please observe the policy on > > open item ownership[1] and send a status update within 72 hours of this > > message. Include a date for your subsequent status update. Testers may > > discover new open items at any time, and I want to plan to get them all > > fixed > > well in advance of shipping 9.6rc1. Consequently, I will appreciate your > > efforts toward speedy resolution. Thanks. > > > > [1] > > http://www.postgresql.org/message-id/20160527025039.ga447...@tornado.leadboat.com > > This PostgreSQL 9.6 open item is past due for your status update. Kindly send > a status update within 24 hours, and include a date for your subsequent status > update. Refer to the policy on open item ownership: > http://www.postgresql.org/message-id/20160527025039.ga447...@tornado.leadboat.com
I'm writing a patch right now, planning to post it later today, commit it tomorrow. Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
