On Thu, Jul 27, 2023 at 10:10 PM Ashutosh Bapat < ashutosh.bapat....@gmail.com> wrote:
> The attached patch (0002) fixes this issue by > 1. declaring child SpecialJoinInfo as a local variable, thus > allocating memory on the stack instead of CurrentMemoryContext. The > memory on the stack is freed automatically. > 2. Freeing the Relids in SpecialJoinInfo explicitly after > SpecialJoinInfo has been used. It doesn't seem too expensive to translate SpecialJoinInfos, so I think it's OK to construct and free the SpecialJoinInfo for a child join on the fly. So the approach in 0002 looks reasonable to me. But there is something that needs to be fixed in 0002. + bms_free(child_sjinfo->commute_above_l); + bms_free(child_sjinfo->commute_above_r); + bms_free(child_sjinfo->commute_below_l); + bms_free(child_sjinfo->commute_below_r); These four members in SpecialJoinInfo only contain outer join relids. They do not need to be translated. So they would reference the same memory areas in child_sjinfo as in parent_sjinfo. We should not free them, otherwise they would become dangling pointers in parent sjinfo. Thanks Richard
