On Mon, 11 Jul 2022 at 20:48, Matthias van de Meent <boekewurm+postg...@gmail.com> wrote: > > 2) v1-002-generation-reduces-memory-consumption.patch > > Reduces memory used by struct GenerationBlock, by minus 8 bits, > > That seems fairly straight-forward -- 8 bytes saved on each page isn't > a lot, but it's something.
I think 002 is likely the only patch here that has some merit. However, it's hard to imagine any measurable performance gains from it. I think the smallest generation block we have today is 8192 bytes. Saving 8 bytes in that equates to a saving of 0.1% of memory. For an 8MB page, it's 1024 times less than that. I imagine Ranier has been working on this due the performance regression mentioned in [1]. I think it'll be much more worthwhile to aim to reduce the memory chunk overheads rather than the block overheads, as Ranier is doing here. I posted a patch in [2] which does that. To make that work, I need to have the owning context in the block. The 001 and 003 patch seems to remove those here. David [1] https://www.postgresql.org/message-id/caaphdvqxplzav6duer5vo_rbh_fehrhmlhigvqxw9jhcykp...@mail.gmail.com [2] https://www.postgresql.org/message-id/CAApHDvpjauCRXcgcaL6+e3eqecEHoeRm9D-kcbuvBitgPnW=v...@mail.gmail.com
