On March 3, 2018 6:36:51 PM PST, Tomas Vondra <tomas.von...@2ndquadrant.com> wrote: >On 03/04/2018 03:20 AM, Thomas Munro wrote: >> Hi, >> >> I saw a one-off failure like this: >> >> QUERY PLAN >> >-------------------------------------------------------------------------- >> Aggregate (actual rows=1 loops=1) >> ! -> Nested Loop (actual rows=98000 loops=1) >> -> Seq Scan on tenk2 (actual rows=10 loops=1) >> Filter: (thousand = 0) >> Rows Removed by Filter: 9990 >> ! -> Gather (actual rows=9800 loops=10) >> Workers Planned: 4 >> Workers Launched: 4 >> -> Parallel Seq Scan on tenk1 (actual rows=1960 >loops=50) >> --- 485,495 ---- >> QUERY PLAN >> >-------------------------------------------------------------------------- >> Aggregate (actual rows=1 loops=1) >> ! -> Nested Loop (actual rows=97984 loops=1) >> -> Seq Scan on tenk2 (actual rows=10 loops=1) >> Filter: (thousand = 0) >> Rows Removed by Filter: 9990 >> ! -> Gather (actual rows=9798 loops=10) >> Workers Planned: 4 >> Workers Launched: 4 >> -> Parallel Seq Scan on tenk1 (actual rows=1960 >loops=50) >> >> >> Two tuples apparently went missing. >> >> Similar failures on the build farm: >> >> >https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=okapi&dt=2018-03-03%2020%3A15%3A01 >> >https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=locust&dt=2018-03-03%2018%3A13%3A32 >> >https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=prairiedog&dt=2018-03-03%2017%3A55%3A11 >> >> Could this be related to commit >> 34db06ef9a1d7f36391c64293bf1e0ce44a33915 or commit >> 497171d3e2aaeea3b30d710b4e368645ad07ae43? >> > >I think the same failure (or at least very similar plan diff) was >already mentioned here: > >https://www.postgresql.org/message-id/17385.1520018...@sss.pgh.pa.us > >So I guess someone else already noticed, but I don't see the cause >identified in that thread.
Robert and I started discussing it a bit over IM. No conclusion. Robert tried to reproduce locally, including disabling atomics, without luck. Can anybody reproduce locally? Andres -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
