Comments on: Slides and audio: How MySQL Handles ORDER BY, GROUP BY, and DISTINCT http://s.petrunia.net/blog/?p=30 Random observations made while working on MySQL / MariaDB query optimizer Sat, 04 Sep 2010 18:25:03 +0000 http://wordpress.org/?v=2.0.12-alpha by: Rick James http://s.petrunia.net/blog/?p=30#comment-33589 Sat, 27 Sep 2008 06:06:59 +0000 http://s.petrunia.net/blog/?p=30#comment-33589 What about ORDER BY NULL ? It turns off certain sorts? Perhaps even the "ORDER BY group_by_list is guaranteed for free" (slide 12)? Won't GROUP BY sometimes use a hash, thereby have to do extra work to guarantee ORDER BY? What about ORDER BY NULL ? It turns off certain sorts? Perhaps even the “ORDER BY group_by_list is guaranteed for free” (slide 12)?

Won’t GROUP BY sometimes use a hash, thereby have to do extra work to guarantee ORDER BY?

]]> by: Pythian Group Blog » Blog Archive » Log Buffer #75: a Carnival of the Vanities for DBAs http://s.petrunia.net/blog/?p=30#comment-13818 Fri, 14 Dec 2007 18:35:26 +0000 http://s.petrunia.net/blog/?p=30#comment-13818 [...] Sergey Petrunia makes available audio and slides from his presentation, How MySQL Handles ORDER BY, GROUP BY, and DISTINCT. [...] […] Sergey Petrunia makes available audio and slides from his presentation, How MySQL Handles ORDER BY, GROUP BY, and DISTINCT. […]

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