On Wed, Aug 6, 2014 at 10:36 PM, Peter Geoghegan <p...@heroku.com> wrote: > This *almost* applies to patched Postgres if you pick a benchmark that > is very sympathetic to my patch. To my surprise, work_mem = '10MB' > (which results in an external tape sort) is sometimes snapping at the > heels of a work_mem = '5GB' setting (which results in an in-memory > quicksort).
Note that this was with a default temp_tablespaces setting that wrote temp files on my home partition/SSD. With a /dev/shm/ temp tablespace, tape sort edges ahead, and has a couple of hundred milliseconds on quicksort for this test case. It's actually faster. -- 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
