-----Original Message----- From: Peter Geoghegan [mailto:peter.geoghega...@gmail.com] Sent: Friday, March 08, 2013 12:00 PM To: Bruce Momjian Cc: Dann Corbit; Robert Haas; Tom Lane; PG Hackers Subject: Re: [HACKERS] Why do we still perform a check for pre-sorted input within qsort variants?
On 8 March 2013 11:48, Bruce Momjian <br...@momjian.us> wrote: > On Fri, Mar 8, 2013 at 07:43:10PM +0000, Dann Corbit wrote: >> I seem to recall that a year or two back some study was done on >> quicksort methodology as used in PostgreSQL. As I recall, the >> algorithm used in PostgreSQL fared well in the tests. > > Well, that's good to hear. I wouldn't mind taking a look at that. We're not the only ones that use (more or less) that same algorithm. I noticed that Redis does so too, just for example (though they didn't get wise to the problems with the "swap_cnt" pessimisation). >> Turns out, it was a lot longer ago than I thought (2005!). The thread was called "Which qsort is used", but I also seem to recall that the topic was revisited a few times. See, for instance: http://www.postgresql.org/message-id/pine.lnx.4.58.0512121138080.18...@eon.cs http://www.cs.toronto.edu/~zhouqq/postgresql/sort/sort.html << -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
