On Wed, Sep 21, 2022 at 02:10:42PM +0700, a.kozhemya...@postgrespro.ru wrote: > After analyzing this, I found out why we don't reach that Assert but we have > coverage shown - firstly, it reached via another test, vacuum; secondly, it > depends on the gcc optimization flag. We reach that Assert only when using > -O0. > If we build with -O2 or -Og that function is not reached (due to different > results of the heap_prune_satisfies_vacuum() check inside > heap_page_prune()).
With "make check MAX_CONNECTIONS=1", does that difference between -O0 and -O2 still appear? Compiler optimization shouldn't consistently change pruning decisions. It could change pruning decisions probabilistically, by changing which parallel actions overlap. If the difference disappears under MAX_CONNECTIONS=1, the system is likely fine.
