On Sat, Feb 22, 2025 at 11:13 AM Amit Langote <amitlangot...@gmail.com> wrote: > On Sat, Feb 22, 2025 at 12:55 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > > Amit Langote <amitlangot...@gmail.com> writes: > > > The short of it is that the cached-plan-inval test in the > > > delay_execution suite can never be made to work under > > > CLOBBER_CACHE_ALWAYS. The test assumes that locks on partitions for a > > > reused generic plan are not taken until InitPlan(). However, under > > > CLOBBER_CACHE_ALWAYS, generic plans are never reused, so the test's > > > assumption never holds. > > > > Ugh. > > > > > I see two possible ways to address this: > > > > > 1. Find a way to disable the cached-plan-inval test in > > > CLOBBER_CACHE_ALWAYS builds. However, I haven't found any other test > > > that does this. > > > > > 2. Remove the test altogether, though that might be too drastic. > > > > Well, you could force matters with "set debug_discard_caches = 0" > > within the test, but I think that's just a band-aid that would > > not make the test fully stable. The point of CLOBBER_CACHE_ALWAYS > > is to model random arrival of cache flush events, which is *always* > > a possibility due to background activity (autovacuum for instance). > > > > We do have a couple of other regression tests that rely on > > "set debug_discard_caches = 0", and I've not seen many buildfarm > > failures tracing to that, but I don't trust it a whole lot. > > > > How badly do you want to keep this test case? It seems fairly > > rickety to me, even without this particular concern. > > Hmm, yeah, I have to admit that even if we address this specific > issue, the risk of this test failing again outweighs the likelihood of > it catching a real breakage in the deferred lock mechanism. > > I'll remove the test for now.
Done. I'll try to think of a more robust testing approach for this, but I’m not very optimistic :-(. -- Thanks, Amit Langote
