Robert Haas <robertmh...@gmail.com> wrote: > So should we give up on this patch? No, this is not news; just confirmation of the earlier gut feelings and less convincing statistics that there is no problem. Tom's argument that if there's no slowdown for common cases, preventing O(N^2) behavior for extreme cases is compelling for me, and we've beaten up on it enough for me to feel comfortable that it doesn't break anything. I held off on investigating the artificial extreme cases when I thought we might possibly have a small performance problem here; but this statistics exercise has just gotten me from "gut feel" that it was noise and "not having 90% confident that we made things worse" to "90% of the time noise would produce a bigger difference". It's one thing to require 90% confidence that an improvement is real before accepting something, it's another to accept a change on the basis of not having 90% confidence that there is degradation -- so I wanted to see a more compelling statistic. Personally, I'm happy with it being in "Ready for Committer" status. I remember someone else on the thread saying that besides the elimination of O(N^2) behavior, it provided better structure for future enhancements. I'll run a few more benchmarks over the next few weeks to try to characterize the improvements in extreme cases, "just for the record", but I don't think we want to wait for that; we've got justification enough as is. -Kevin
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