On Mon, Nov 27, 2023 at 6:35 AM Alexander Korotkov <aekorot...@gmail.com> wrote: > > On Fri, Nov 24, 2023 at 3:54 PM Alexander Korotkov <aekorot...@gmail.com> > wrote: > > > > On Thu, Nov 23, 2023 at 4:33 AM Richard Guo <guofengli...@gmail.com> wrote: > > > > > > On Sun, Nov 19, 2023 at 9:17 AM Alexander Korotkov <aekorot...@gmail.com> > > > wrote: > > >> > > >> It's here. New REALLOCATE_BITMAPSETS forces bitmapset reallocation on > > >> each modification. > > > > > > > > > +1 to the idea of introducing a reallocation mode to Bitmapset. > > > > > >> > > >> I had the feeling of falling into a rabbit hole while debugging all > > >> the cases of failure with this new option. With the second patch > > >> regressions tests pass. > > > > > > > > > It seems to me that we have always had situations where we share the > > > same pointer to a Bitmapset structure across different places. I do not > > > think this is a problem as long as we do not modify the Bitmapsets in a > > > way that requires reallocation or impact the locations sharing the same > > > pointer. > > > > > > So I'm wondering, instead of attempting to avoid sharing pointer to > > > Bitmapset in all locations that have problems, can we simply bms_copy > > > the original Bitmapset within replace_relid() before making any > > > modifications, as I proposed previously? Of course, as Andres pointed > > > out, we need to do so also for the "Delete relid without substitution" > > > path. Please see the attached. > > > > > > Yes, this makes sense. Thank you for the patch. My initial point was > > that replace_relid() should either do in-place in all cases or make a > > copy in all cases. Now I see that it should make a copy in all cases. > > Note, that without making a copy in delete case, regression tests fail > > with REALLOCATE_BITMAPSETS on. > > > > Please, find the revised patchset. As Ashutosh Bapat asked, asserts > > are split into separate patch. > > Any objections to pushing this? >
Did we at least measure the memory impact? How do we ensure that we are not making unnecessary copies of Bitmapsets? -- Best Wishes, Ashutosh Bapat
