On Tue, Sep 6, 2016 at 10:36 PM, Peter Geoghegan <p...@heroku.com> wrote: > Well, maybe, but the whole idea behind replacement_sort_tuples (by > which I mean the continued occasional use of replacement selection by > Postgres) was that we hope to avoid a merge step *entirely*. This new > merge shift down heap patch could make the merge step so cheap as to > be next to free anyway (in the even of presorted input)
I mean: Cheaper than just processing the tuples to return to caller without comparisons/merging (within the TSS_SORTEDONTAPE path). I do not mean free in an absolute sense, of course. -- 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
