On Tue, Apr 30, 2024 at 7:17 AM Thomas Munro <thomas.mu...@gmail.com> wrote: > On Tue, Apr 30, 2024 at 6:47 AM Maksim Milyutin <milyuti...@gmail.com> wrote: > >> Should not we call at the end the StrategyFreeBuffer() function to add > >> target buffer to freelist and not miss it after invalidation? > > > Please take a look at this issue, current implementation of > > EvictUnpinnedBuffer() IMO is erroneous - evicted buffers are lost > > permanently and will not be reused again
I don't think that's true: it is not lost permanently, it'll be found by the regular clock hand. Perhaps it should be put on the freelist so it can be found again quickly, but I'm not sure that's a bug, is it? If it were true, even basic testing eg select count(pg_buffercache_evict(bufferid)) from pg_buffercache would leave the system non-functional, but it doesn't, the usual CLOCK algorithm just does its thing.
