On Sat, May 2, 2026 at 6:37 PM Daniil Davydov <[email protected]> wrote: > On Sat, May 2, 2026 at 9:16 PM Alexander Korotkov <[email protected]> > wrote: > > > > Thank you for your feedback. I think the scope of this patch is well > > described in [1]. We don't want to restrict the superuser from > > something, but our buffer manager just technically can't access the > > local buffers of other sessions. Read streams introduced a new code > > path for reading relations, which was lacking of the proper check for > > local buffers of other sessions. And this patch attempts to fix that. > > DROP TABLE is an exclusion. It actually don't need to read contents > > of buffers, just drop them. And DropRelationBuffers() have a special > > exclusion for this case. So, DROP TABLE appears to be the only > > operation that makes sense, it's a conscious exclusion, and there is > > no intention to forbid it. > > Yep, exactly. > > > I've revised the patch. 0001 contains tests and states the current > > behavior. 0002 contains fix and the corresponding changes in the > > tests. I made a change in 0001: removed the check in > > ReadBufferExtended(). We added the same check to ReadBuffer_common(), > > and I don't think it makes sense to do this check twice in the row. > > Thank you! But I'm afraid that you forgot to attach the patches..
Here they are. > BTW, what do you think about this proposal? : > > On the other hand, we have an error message that says "cannot access...", > > which > > may look like every kind of "access" is forbidden. I bet that this is the > > place > > that has confused you. More accurate error message would be "cannot access > > pages..." or "cannot access content...". I think we can change our error > > message in this way. What do you think? > > We can easily include it in the first patch. This is possible, but I would keep that in a separate patch. We now have clear scope for both patches: 0001 includes additional tests, 0002 fixes the bug and restores old behavior. ------ Regards, Alexander Korotkov Supabase
v20-0002-Prevent-access-to-other-sessions-temp-tables.patch
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v20-0001-Add-tests-for-cross-session-temp-table-access.patch
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