Richard Guo <guofengli...@gmail.com> writes: > +1. I'm kind of worried that the expansion of parallelization could > lead to more instances of instability. Alexander mentioned one such > case at [1]. I haven't looked into it though. > [1] > https://www.postgresql.org/message-id/cbf0156f-5aa1-91db-5802-82435dda03e6%40gmail.com
The mechanism there is pretty obvious: a plancache flush happened at just the wrong (right?) time and caused the output to change, as indeed the comment acknowledges: -- currently, this fails due to cached plan for "r.f1 + 1" expression -- (but if debug_discard_caches is on, it will succeed) I wonder if we shouldn't just remove that test case as being too unstable -- especially since it's not proving much anyway. regards, tom lane