On Fri, Jul 15, 2022 at 11:22 PM Maciek Sakrejda <m.sakre...@gmail.com> wrote:
> I ran that original test case with and without the patch. Here are the > numbers I'm seeing: > > master (best of three): > > postgres=# SELECT count(*) FROM lotsarows; > Time: 582.423 ms > > postgres=# EXPLAIN (ANALYZE, TIMING OFF) SELECT count(*) FROM lotsarows; > Time: 616.102 ms > > postgres=# EXPLAIN (ANALYZE, TIMING ON) SELECT count(*) FROM lotsarows; > Time: 1068.700 ms (00:01.069) > > patched (best of three): > > postgres=# SELECT count(*) FROM lotsarows; > Time: 550.822 ms > > postgres=# EXPLAIN (ANALYZE, TIMING OFF) SELECT count(*) FROM lotsarows; > Time: 612.572 ms > > postgres=# EXPLAIN (ANALYZE, TIMING ON) SELECT count(*) FROM lotsarows; > Time: 690.875 ms > > On Fri, Jul 1, 2022 at 10:26 AM Andres Freund <and...@anarazel.de> wrote: > > On 2022-07-01 01:23:01 -0700, Lukas Fittl wrote: > >... > > > Known WIP problems with this patch version: > > > > > > * There appears to be a timing discrepancy I haven't yet worked out, > where > > > the \timing data reported by psql doesn't match what EXPLAIN ANALYZE > is > > > reporting. With Andres' earlier test case, I'm seeing a consistent > ~700ms > > > higher for \timing than for the EXPLAIN ANALYZE time reported on the > > > server > > > side, only when rdtsc measurement is used -- its likely there is a > problem > > > somewhere with how we perform the cycles to time conversion > > > > Could you explain a bit more what you're seeing? I just tested your > patches > > and didn't see that here. > > I did not see this either, but I did see that the execution time > reported by \timing is (for this test case) consistently 0.5-1ms > *lower* than the Execution Time reported by EXPLAIN. I did not see > that on master. Is that expected? > > Thanks, > Maciek > > > The patch requires a rebase; please rebase the patch with the latest code. Hunk #5 succeeded at 147 with fuzz 2 (offset -3 lines). Hunk #6 FAILED at 170. Hunk #7 succeeded at 165 (offset -69 lines). 2 out of 7 hunks FAILED -- saving rejects to file src/include/portability/instr_time.h.rej patching file src/tools/msvc/Mkvcbuild.pm -- Ibrar Ahmed
