On Thu, Apr 10, 2014 at 06:03:15PM +0100, Simon Riggs wrote: > On 6 February 2014 18:21, Jeff Janes <jeff.ja...@gmail.com> wrote: > > On Tue, Feb 4, 2014 at 2:22 PM, Jeremy Harris <j...@wizmail.org> wrote: > >> > >> The attached patch replaces the existing siftup method for heapify with > >> a siftdown method. Tested with random integers it does 18% fewer > >> compares and takes 10% less time for the heapify, over the work_mem > >> range 1024 to 1048576. > > > > > > Thanks for working on this. > > +1 > > Your patch isn't linked properly from the CF manager though. > > If you like patches like this then there's a long(er) list of > optimizations already proposed previously around sorting. It would be > good to have someone work through them for external sorts. I believe > Noah is working on parallel internal sort (as an aside). > > There's also an optimization possible for merge joins where we use the > output of the first sort as an additional filter on the second sort. > That can help when we're going to join two disjoint tables.
Where should this be recorded? TODO? Commitfest manager? -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
