Comments on: Working around MySQL’s horrible “ORDER BY rand()” in Django http://seanoc.wordpress.com/2008/01/27/working-around-mysqls-horrible-order-by-rand-in-django/ Some words from a simple web develper. Wed, 27 May 2009 01:20:32 +0000 http://wordpress.com/ hourly 1 By: Sean O'Connor http://seanoc.wordpress.com/2008/01/27/working-around-mysqls-horrible-order-by-rand-in-django/#comment-24 Sean O'Connor Mon, 28 Jan 2008 03:02:11 +0000 http://seanoc.com/archive/2008/01/27/working-around-mysqls-horrible-order-by-rand-in-django/#comment-24 Martin: As far as I know Postgres is smarter/faster at doing randomly ordered selects but do some experimentation. If you get the performance you are looking for then great, otherwise this solution may be for you. David: Very cool, there are actually a few places in my code where I do that, just didn't happen to come across it when I grabbed this example. Thanks for the tip. Bjorn: Also a cool solution, nice work. Martin: As far as I know Postgres is smarter/faster at doing randomly ordered selects but do some experimentation. If you get the performance you are looking for then great, otherwise this solution may be for you.

David: Very cool, there are actually a few places in my code where I do that, just didn’t happen to come across it when I grabbed this example. Thanks for the tip.

Bjorn: Also a cool solution, nice work.

]]> By: Bjorn Kempen http://seanoc.wordpress.com/2008/01/27/working-around-mysqls-horrible-order-by-rand-in-django/#comment-23 Bjorn Kempen Sun, 27 Jan 2008 10:54:59 +0000 http://seanoc.com/archive/2008/01/27/working-around-mysqls-horrible-order-by-rand-in-django/#comment-23 I made a blog post about pretty much the same thing a few days ago. Might be an interesting read :) http://blog.buffis.com/?p=64 I made a blog post about pretty much the same thing a few days ago. Might be an interesting read :)
http://blog.buffis.com/?p=64

]]> By: David Buxton http://seanoc.wordpress.com/2008/01/27/working-around-mysqls-horrible-order-by-rand-in-django/#comment-22 David Buxton Sun, 27 Jan 2008 10:46:58 +0000 http://seanoc.com/archive/2008/01/27/working-around-mysqls-horrible-order-by-rand-in-django/#comment-22 You missed a chance to use my favourite Python-ism: list comprehensions. Last few lines could be written like this: rows = cursor.fetchall() picture_ids = [row[0] for row in random.sample(rows, 6)] pictures = user.picture_set.filter(id__in=picture_ids) You missed a chance to use my favourite Python-ism: list comprehensions. Last few lines could be written like this:

rows = cursor.fetchall()
picture_ids = [row[0] for row in random.sample(rows, 6)]
pictures = user.picture_set.filter(id__in=picture_ids)

]]> By: Martin http://seanoc.wordpress.com/2008/01/27/working-around-mysqls-horrible-order-by-rand-in-django/#comment-25 Martin Sun, 27 Jan 2008 08:28:03 +0000 http://seanoc.com/archive/2008/01/27/working-around-mysqls-horrible-order-by-rand-in-django/#comment-25 Is it ok to use pictures = User.picture_set.filter(private=False).order_by('?')[:6] with postgres? Is it ok to use pictures = User.picture_set.filter(private=False).order_by(‘?’)[:6] with postgres?

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