On Wed, Apr 26, 2017 at 11:39 AM, Alexander Korotkov <a.korot...@postgrespro.ru> wrote: > But I'd like to make incremental sort not slower than quicksort in case of > presorted data. New idea about it comes to my mind. Since cause of > incremental sort slowness in this case is too frequent reset of tuplesort, > then what if we would artificially put data in larger groups. Attached > revision of patch implements this: it doesn't stop to accumulate tuples to > tuplesort until we have MIN_GROUP_SIZE tuples. > > Now, incremental sort is not slower than quicksort. And this seems to be > cool. > However, in the LIMIT case we will pay the price of fetching some extra > tuples from outer node. But, that doesn't seem to hurt us too much. > > Any thoughts?
Nice idea. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
