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Re: Double Index Performance
Posted by: Sebastien Caisse
Date: January 16, 2006 06:24AM

You could:
a) Make PostDate NOT NULL (MySQL supports a "0" date value).
b) CREATE a DESC non-UNIQUE INDEX for postDate
c) or better yet, CREATE a non-UNIQUE INDEX for (postDate DESC, PersonId DESC).

Though the MAX(PostDate) might be faster, from personal experience most of the time a LIMIT 1 has been shown to be faster, as it avoid the whole aggragetion processing...



Edited 1 time(s). Last edit at 01/16/2006 06:26AM by Sebastien Caisse.

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