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From:Zhigang Zhang Date:February 12 2014 1:23am
Subject:LIKE sql optimization
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For example:

 

Select * from T where col like ‘%abcd’;

 

The table T is myisam table and we created a index on col.

 

As we known, this like sql does not use the index created on col, it confuse
me, why?

 

I think in mysiam engine, the index data is smaller, it can use index link
list to optimize it so as to reduce the disk scan than to the whole table
scan.

 

Thanks.

 

Zhigang


Thread
LIKE sql optimizationZhigang Zhang12 Feb 2014
  • Re: LIKE sql optimizationReindl Harald12 Feb 2014
  • Re: LIKE sql optimizationMathieu Desharnais12 Feb 2014
    • RE: LIKE sql optimizationZhigang Zhang12 Feb 2014
      • Re: LIKE sql optimizationkitlenv12 Feb 2014
        • Re: LIKE sql optimizationlouis liu12 Feb 2014
          • Re: LIKE sql optimizationMathieu Desharnais12 Feb 2014
      • Re: LIKE sql optimizationReindl Harald12 Feb 2014
        • RE: LIKE sql optimizationZhigang Zhang12 Feb 2014
      • Re: LIKE sql optimizationMorgan Tocker12 Feb 2014
        • RE: LIKE sql optimizationZhigang Zhang12 Feb 2014
        • Re: LIKE sql optimizationJesper Wisborg Krogh12 Feb 2014
          • RE: LIKE sql optimizationZhigang Zhang12 Feb 2014