Re: Air-traffic benchmark
От
hubert depesz lubaczewski
Тема
Re: Air-traffic benchmark
Дата
Msg-id
20100107233933.GA19526@depesz.com
Ответ на
Air-traffic benchmark (Lefteris)
Список
Дерево обсуждения
Air-traffic benchmark Lefteris <lsidir@gmail.com>
Re: Air-traffic benchmark Simon Riggs <simon@2ndQuadrant.com>
Re: Air-traffic benchmark "Gurgel, Flavio" <flavio@4linux.com.br>
Re: Air-traffic benchmark "A. Kretschmer" <andreas.kretschmer@schollglas.com>
Re: Air-traffic benchmark Lefteris <lsidir@gmail.com>
Re: Air-traffic benchmark "A. Kretschmer" <andreas.kretschmer@schollglas.com>
Re: Air-traffic benchmark hubert depesz lubaczewski <depesz@depesz.com>
Re: Air-traffic benchmark Greg Smith <greg@2ndquadrant.com>
Re: Air-traffic benchmark Arjen van der Meijden <acmmailing@tweakers.net>
Re: Air-traffic benchmark Lefteris <lsidir@gmail.com>
Re: Air-traffic benchmark "A. Kretschmer" <andreas.kretschmer@schollglas.com>
Re: Air-traffic benchmark Jochen Erwied <jochen@pgsql-performance.erwied.eu>
Re: Air-traffic benchmark Lefteris <lsidir@gmail.com>
Re: Air-traffic benchmark Alvaro Herrera <alvherre@commandprompt.com>
Re: Air-traffic benchmark Alvaro Herrera <alvherre@commandprompt.com>
Re: Air-traffic benchmark Craig James <craig_james@emolecules.com>
Re: Air-traffic benchmark Lefteris <lsidir@gmail.com>
Re: Air-traffic benchmark Ivan Voras <ivoras@freebsd.org>
Re: Air-traffic benchmark Lefteris <lsidir@gmail.com>
Re: Air-traffic benchmark Grzegorz Jaśkiewicz <gryzman@gmail.com>
Re: Air-traffic benchmark Ivan Voras <ivoras@freebsd.org>
Re: Air-traffic benchmark Lefteris <lsidir@gmail.com>
Re: Air-traffic benchmark Greg Smith <greg@2ndquadrant.com>
Re: Air-traffic benchmark Lefteris <lsidir@gmail.com>
Re: Air-traffic benchmark Lefteris <lsidir@gmail.com>
On Thu, Jan 07, 2010 at 01:38:41PM +0100, Lefteris wrote: > airtraffic=# EXPLAIN ANALYZE SELECT "DayOfWeek", count(*) AS c FROM > ontime WHERE "Year" BETWEEN 2000 AND 2008 GROUP BY "DayOfWeek" ORDER > BY c DESC; Well, this query basically has to be slow. Correct approach to this problem is to add precalculated aggregates - either with triggers or with some cronjob. Afterwards query speed depends only on how good are your aggregates, and/or how detailed. Of course calculating them is not free, but is done on write (or periodically), and not on user-request, which makes user-requests *much* faster. depesz -- Linkedin: http://www.linkedin.com/in/depesz / blog: http://www.depesz.com/ jid/gtalk: depesz@depesz.com / aim:depeszhdl / skype:depesz_hdl / gg:6749007
В списке pgsql-performance по дате отправления
