On Mon, 14 Apr 2025, Tom Lane wrote:
I wrote:
Here's a draft patch for this. It seems to fix the problem in
light testing.
I realized that the "repro" I had for this isn't testing the same
thing that Dimitrios is seeing; what it is exposing looks more like
a bug or at least a behavioral change due to the v18 work to record
not-null constraints in pg_constraint [1]. So my patch may fix his
problem or it may not. It would be good to have a reproducer that
fails (not necessarily every time) in v17 or earlier.
Thank you for your work on it.
I only got the "ERROR: deadlock detected" message once, with pg_restore
compiled from master branch. My dump is too large to test it many times on
v17 so I can't tell if it occurs there.
In general I believe that dependency resolution is not optimal, either
there is a deadlock bug or not. It can definitely be improved as work
(mostly post-data) is not parallelized as much as it can.
Anyway if I get the deadlock on v17 I'll update the initial thread.
Thanks,
Dimitris
