On Mon, Feb 25, 2013 at 02:31:21PM +0000, Peter Geoghegan wrote: > On 25 February 2013 11:49, Robert Haas <robertmh...@gmail.com> wrote: > > I did attempt to do some tinkering with this while I was playing with > > it, but I didn't come up with anything really compelling. You can > > reduce the number of comparisons on particular workloads by tinkering > > with the algorithm, but then somebody else ends up doing more > > comparisons, so it's hard to say whether you've really made things > > better. Or at least I found it so. > > Right. > > To be honest, the real reason that it bothers me is that everything > else that our qsort routine does that differs from classic quicksort > (mostly quadratic insurance, like the median-of-medians pivot > selection, but also the fallback to insertion sort when n < 7) is very > well supported by peer reviewed research. Like Tom, I find it > implausible that Sedgewick and others missed a trick, where we did > not, particularly with something so simple.
Perhaps we are more likely to be fed sorted data than a typical qsort usecase. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
