On Wed, Apr 26, 2017 at 10:10 AM, Alexander Korotkov <a.korot...@postgrespro.ru> wrote: > OK, I get it. Our qsort is so fast not only on 100% presorted case. > However, that doesn't change many things in context of incremental sort.
The important point is to make any presorted test case only ~99% presorted, so as to not give too much credit to the "high risk" presort check optimization. The switch to insertion sort that we left in (not the bad one removed by a3f0b3d -- the insertion sort that actually comes from the B&M paper) does "legitimately" make sorting faster with presorted cases. -- Peter Geoghegan VMware vCenter Server https://www.vmware.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
