Greetings, * Robert Haas (robertmh...@gmail.com) wrote: > On Mon, Oct 11, 2021 at 1:30 PM Stephen Frost <sfr...@snowman.net> wrote: > > Regarding unlogged LSNs at least, I would think that we'd want to > > actually use GetFakeLSNForUnloggedRel() instead of just having it zero'd > > out. The fixed value for GiST index pages is just during the index > > build process, as I recall, and that's perhaps less of a concern. Part > > of the point of using XTS is to avoid the issue of the LSN not being > > changed when hint bits are, or more generally not being unique in > > various cases. > > I don't believe there's anything to prevent the fake-LSN counter from > overtaking the real end-of-WAL, and if that should happen, then the > buffer manager would get confused. Maybe that can be fixed by doing > some sort of surgery on the buffer manager, but it doesn't seem to be > a trivial or ignorable problem.
Using fake LSNs isn't new.. how is this not a concern already then? Also wondering why the buffer manager would care about the LSN on pages which are not BM_PERMANENT..? I'll admit that I might certainly be missing something here. Thanks, Stephen
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