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From:Dave Dyer Date:August 30 2011 7:57pm
Subject:Re: utility of an index
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At 12:43 AM 8/30/2011, mysql-plain-digest-help@stripped wrote:
>Not useful to add an index for that. I also wonder why the value is null 
>(meaning: unknown, not certain) for almost all records. 

It depends on if you want the forest or the trees.  A frequently executed
query asks for just the robots.  An index is an efficient way to select
6 of 20,000.      As for why the rest are null, null is just a a random
everything else value, left over from before the "is_robot" column was
added. 

Is there a better way to mark a small number of "special" records in a
big data set? 

Thread
Re: utility of an indexDave Dyer30 Aug
Re: utility of an indexJohan De Meersman31 Aug