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From:Michael T. Babcock Date:November 18 2002 9:22pm
Subject:Re: feature suggestion - indexes with "where" clause or similar
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Neulinger, Nathan wrote:

>It's actually relatively speedy WITH the bad index, but maintaining that
>index (given it's lopsided nature) is very expensive. 
>
>Yes, the point is to ONLY index the row if it matches the restriction.
>  
>

To clarify, if MySQL is indexing a binary value with lopsided 
distribution, simply only keep an index of record locations for the 
less-likely value.  The more-likely value will end up being table-scanned.

'true', 'true', 'false', 'true', 'true', 'true'
... 'false' -> 3rd row.
... 'true' -> read the whole thing.

-- 
Michael T. Babcock
C.T.O., FibreSpeed Ltd.
http://www.fibrespeed.net/~mbabcock


Thread
feature suggestion - indexes with "where" clause or similarNathan Neulinger15 Nov
  • re: feature suggestion - indexes with "where" clause or similarEgor Egorov18 Nov
    • Re: feature suggestion - indexes with "where" clause or similarJeremy Zawodny18 Nov
Re: feature suggestion - indexes with "where" clause or similarDaniel Koch18 Nov
  • RE: feature suggestion - indexes with "where" clause or similarDean Harding18 Nov
    • Re: feature suggestion - indexes with "where" clause or similarJeremy Zawodny18 Nov
RE: feature suggestion - indexes with "where" clause or similarNathan Neulinger18 Nov
  • Re: feature suggestion - indexes with "where" clause or similarMichael T. Babcock18 Nov
    • Re: feature suggestion - indexes with "where" clause or similarDaniel Koch19 Nov
      • Re: feature suggestion - indexes with "where" clause or similarBenjamin Pflugmann19 Nov
        • Re: feature suggestion - indexes with "where" clause or similarDan Nelson19 Nov