MySQL Forums
Forum List  »  Performance

Advanced Search
New Topic

Re: MySQL rand() is slow on large datasets
Posted by: Thomas Baggelaar
Date: July 24, 2007 08:28AM

Maybe this can help you with your performance issue

This query:

SELECT * FROM `table` WHERE id >= (SELECT FLOOR( MAX(id) * RAND()) FROM `table` ) ORDER BY id LIMIT 1;

should be much faster than this query:

SELECT * FROM `table` ORDER BY RAND() LIMIT 1;

See also: http://forums.mysql.com/read.php?10,163708,163708#msg-163708

Navigate: Previous Message• Next Message
Options: Reply• Quote


Subject
Views
Written By
Posted
MySQL rand() is slow on large datasets
19163
pbu pbu
July 24, 2007 08:19AM
Re: MySQL rand() is slow on large datasets
14555
Thomas Baggelaar
July 24, 2007 08:28AM
Re: MySQL rand() is slow on large datasets
7984
Maurizio G
September 02, 2007 10:30AM
Re: MySQL rand() is slow on large datasets
10332
Jay Paroline
January 18, 2008 12:25AM
Re: MySQL rand() is slow on large datasets
7843
Jeff Fillmore
May 15, 2008 03:15PM
Re: MySQL rand() is slow on large datasets
8712
Mike Pogues
May 12, 2009 10:21AM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.