On Thu, Apr 7, 2016 at 11:10 AM, Robert Haas <robertmh...@gmail.com> wrote: > I prefer units of tuples, with the GUC itself therefore being > unitless. I suggest we call the parameter replacement_sort_threshold > and document that (1) the ideal value may depend on the amount of CPU > cache available to running processes, with more cache implying higher > values; and (2) the ideal value may depend somewhat on the input data, > with more correlation implying higher values. And then pick some > value that you think is likely to work well for most people and call > it good.
I really don't want to bikeshed about this, but I must ask: if the name of the GUC must include the word "threshold", shouldn't it be called quicksort_threshold? My dictionary defines threshold as "any place or point of entering or beginning". But this GUC does not govern where replacement selection begins; it governs where it ends. How do you feel about replacement_sort_tuples? We already use the word "tuple" in the names of GUCs. -- Peter Geoghegan -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
