Robert Haas <robertmh...@gmail.com> writes: > ... Maybe that difference matters to the memory prefetching > controller, I dunno, but it seems funny that we did the PGXACT work to > reduce the number of cache lines that had to be touched in order to > take a snapshot to improve performance, and now we're talking about > increasing it again, also to improve performance.
Yes. I was skeptical that the original change was adequately proven to be a good idea, and I'm even more skeptical this time. I think every single number that's been reported about this is completely machine-specific, and likely workload-specific too, and should not be taken as a reason to do anything. My druthers at this point would be to revert the separation on code cleanliness grounds and call it a day, more or less independently of any claims about performance. I'd be willing to talk about padding PGPROC to some reasonable stride, but I remain dubious that any changes of that sort would have a half-life worth complicating the code for. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers