On Tue, May 7, 2024 at 1:19 PM Richard Guo <guofengli...@gmail.com> wrote: > On Tue, May 7, 2024 at 1:46 PM David Rowley <dgrowle...@gmail.com> wrote: >> >> On Tue, 7 May 2024 at 17:28, Tom Lane <t...@sss.pgh.pa.us> wrote: >> > What I'm trying to figure out here is whether we have a live bug >> > in this area in released branches; and if so, why we've not seen >> > reports of that. >> >> We could check what portions of REALLOCATE_BITMAPSETS are >> backpatchable. It may not be applicable very far back because of v16's >> 00b41463c. The bms_del_member() would have left a zero set rather than >> doing bms_free() prior to that commit. There could be a bug in v16. > > > I also think there might be a bug in v16, as long as > 'sjinfo->syn_lefthand' and 'rinfo->outer_relids' are referencing the > same bitmapset and the content of this bitmapset is altered through > 'sjinfo->syn_lefthand' without 'rinfo->outer_relids' being aware of > these changes. I tried to compose a query that can trigger this bug but > failed though.
Can sjinfo->syn_lefthand became empty set after bms_del_member()? If so, rinfo->outer_relids will become an invalid pointer. If so, it's obviously a bug, while it still might be very hard to make this trigger a segfault. ------ Regards, Alexander Korotkov Supabase
