Hi, On 2021-07-29 13:15:53 -0400, Robert Haas wrote: > I don't know if this is better, but I do kind of like the fact that > the basic representation is just an array. It makes it really easy to > predict how much memory will be needed for a given number of dead > TIDs, and it's very DSM-friendly as well.
I think those advantages are far outstripped by the big disadvantage of needing to either size the array accurately from the start, or to reallocate the whole array. Our current pre-allocation behaviour is very wasteful for most vacuums but doesn't handle large work_mem at all, causing unnecessary index scans. Greetings, Andres Freund
