On Fri, Apr 15, 2016 at 1:59 AM, Alexander Korotkov < a.korot...@postgrespro.ru> wrote:
> On Thu, Apr 14, 2016 at 5:35 AM, Andres Freund <and...@anarazel.de> wrote: > >> On 2016-04-14 07:59:07 +0530, Amit Kapila wrote: >> > What you want to see by prewarming? >> >> Prewarming appears to greatly reduce the per-run variance on that >> machine, making it a lot easier to get meaningful results. Thus it'd >> make it easier to compare pre/post padding numbers. >> >> > Will it have safe effect, if the tests are run for 10 or 15 mins >> > rather than 5 mins? >> >> s/safe/same/? If so, no, I doesn't look that way. The order of buffers >> appears to play a large role; and it won't change in a memory resident >> workload over one run. >> > > I've tried to run read-only benchmark of pad_pgxact_v1.patch on 4x18 Intel > machine. The results are following. > > clients no-pad pad > 1 12997 13381 > 2 26728 25645 > 4 52539 51738 > 8 103785 102337 > 10 132606 126174 > 20 255844 252143 > 30 371359 357629 > 40 450429 443053 > 50 497705 488250 > 60 564385 564877 > 70 718860 725149 > 80 934170 931218 > 90 1152961 1146498 > 100 1240055 1300369 > 110 1207727 1375706 > 120 1167681 1417032 > 130 1120891 1448408 > 140 1085904 1449027 > 150 1022160 1437545 > 160 976487 1441720 > 170 978120 1435848 > 180 953843 1414925 > > snapshot_too_old patch was reverted in the both cases. > On high number of clients padding gives very significant benefit. > These results indicates that the patch is a win. Are these results median of 3 runs or single run data. By the way can you share the output of lscpu command on this m/c. With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
