4 ms·
I know it can happen, but I would expect the result to be a couple percepts. OTOH, I did observe up to 20% randomness based on other choices made by optimizer,
by Const-me 5y ago
I know it can happen, but I would expect the result to be a couple percepts.
OTOH, I did observe up to 20% randomness based on other choices made by optimizer, compiler and linker. In my experience, the main source was different decisions what to inline, especially for release builds with LTO/LTCG. For me, a good workaround was compiler-specific forceinline/noinline function attributes.
However, my C++ code is probably very different from what's in postgres. I usually write and optimize manually vectorized and OpenMP parallelized numeric stuff, FP64 or FP32, doing little to no I/O.