On Thu, Apr 25, 2024 at 7:25 PM Ashutosh Bapat <ashutosh.bapat....@gmail.com> wrote:
> Quickly looking at the function, the patch would make it more apparent > that the function is a noop when mergeclause_list is empty. > Thanks for looking at this patch. Yes, that's what it does. > I haven't looked closely to see if creating unique path nonetheless is > useful somewhere else. > It seems that one of the side effects of create_unique_path is that it caches the generated unique path so that we can avoid creating it repeatedly for the same rel. But this does not seem to justify calling create_unique_path when we know it is unnecessary. Please add to the next commitfest. > Done. > If the patch shows some measurable performance improvement, it would > become more attractive. > I doubt that there is measurable performance improvement. But I found that throughout the run of the regression tests, sort_inner_and_outer is called a total of 44,424 times. Among these calls, there are 11,064 instances where mergeclause_list is found to be empty. This accounts for ~1/4. I think maybe this suggests that it's worth the shortcut as the patch does. Thanks Richard
