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From:Frederik Lindberg Date:January 1 1970 12:00am
Subject:LIKE '%foo%' (was: mysql is a ...)
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On Sun, 14 Nov 1999, Michael Widenius wrote:

> Frederik> internals. Maybe it is very easy to speed up the index scan, or maybe
> Frederik> MySQL incorrectly decides that the index is worthless (even though a
> Frederik> complete index scan is cheaper than a complete data scan).
> 
> The above isn't really true;  If the records are short, it's faster to 
> scan the table than scan the index (as scanning the index involves
> much more seeks)

Yes. I'm usually assuming that the index fits and is cached in memory, but
the table itself is too big.

Back to the original problem: Is there a way to optimized LIKE '%foo%'?


-Sincerely, Fred

Fred Lindberg, Inf. Dis., WashU, St. Louis, MO, USA

Thread
mysql is a pain in the assMark O. Davis26 Oct
  • Re: mysql is a pain in the assEd Carp26 Oct
  • Re: mysql is a pain in the assLindsay Davies26 Oct
  • Re: mysql is a pain in the assfooler26 Oct
  • Re: mysql is a pain in the assBogdan Paduraru26 Oct
  • RE: mysql is a pain in the assDavid Moreno S.26 Oct
  • Re: mysql is a pain in the assJeremy Cole26 Oct
  • Re: mysql is a pain in the assMark Russell26 Oct
  • Re: mysql is a pain in the assMark Russell26 Oct
  • Re: mysql is a pain in the assRuben I Safir26 Oct
  • Re: mysql is a pain in the assRuben I Safir26 Oct
  • Re: mysql is a pain in the assTonu Samuel26 Oct
  • Re: mysql is a pain in the ass(Paul D. Smith)26 Oct
  • Re: mysql is a pain in the assfooler27 Oct
  • Re: mysql is a pain in the assfooler27 Oct
    • Re: mysql is a pain in the assEd Carp27 Oct
  • Re: mysql is a pain in the assfooler27 Oct
  • Re: mysql is a pain in the assfooler27 Oct
    • Re: mysql is a pain in the assEd Carp27 Oct
      • Re: mysql is a pain in the assfooler27 Oct
        • RE: mysql is a pain in the assOzlinx)27 Oct
        • Re: mysql is a pain in the assEd Carp27 Oct
          • Re: mysql is a pain in the assRuben Safir27 Oct
      • Re: mysql is a pain in the assJay J27 Oct
      • Re: mysql is a pain in the assTonu Samuel27 Oct
        • Re: mysql is a pain in the assDan Nelson27 Oct
        • Re: mysql is a pain in the assDan Nelson27 Oct
      • Re: mysql is a pain in the assfooler27 Oct
        • Re: mysql is a pain in the assJani Tolonen27 Oct
          • Priorities on the TODO list [was Re: mysql is a pain in the ass]Bob Kline27 Oct
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        • Full commercial products vs. open source [was Re: mysql is a painin the ass]Bob Kline27 Oct
        • RE: mysql is a pain in the assOzlinx)28 Oct
      • Re: mysql is a pain in the assJay J27 Oct
      • Re: mysql is a pain in the assTonu Samuel27 Oct
      • Re: mysql is a pain in the assTonu Samuel27 Oct
      • Re: mysql is a pain in the assfooler27 Oct
        • Re: mysql is a pain in the assBob Kline27 Oct
        • Re: mysql is a pain in the assRuben Safir27 Oct
        • Re: mysql is a pain in the assMike Schwartz28 Oct
          • Re: mysql is a pain in the assJani Tolonen28 Oct
            • Re: mysql is a pain in the assMike Schwartz29 Oct
              • Re: mysql is a pain in the assFrederik Lindberg29 Oct
                • Re: mysql is a pain in the assMike Schwartz29 Oct
                  • Re: mysql is a pain in the assFrederik Lindberg29 Oct
                    • Re: mysql is a pain in the assMichael Widenius14 Nov
                      • LIKE '%foo%' (was: mysql is a ...)Frederik Lindberg14 Nov
                  • Re: mysql is a pain in the assMichael Widenius14 Nov
                    • Re: mysql is a pain in the assBob Kline14 Nov
      • Re: mysql is a pain in the assTonu Samuel28 Oct
      • Re: mysql is a pain in the assfooler29 Oct
        • Hardware vs Software and the speedJani Tolonen29 Oct
      • Re: Hardware vs Software and the speedfooler29 Oct
        • Re: Hardware vs Software and the speedJani Tolonen29 Oct
      • Re: mysql is a pain in the asssasha29 Oct
      • Re: Hardware vs Software and the speedfooler30 Oct
        • Re: Hardware vs Software and the speedJani Tolonen1 Nov
      • Re: mysql is a pain in the assDuncan Kinder30 Oct
  • Re: mysql is a pain in the assSabat27 Oct
  • Re: mysql is a pain in the ass(Paul D. Smith)27 Oct
Re: mysql is a pain in the assOzlinx)26 Oct
RE: mysql is a pain in the assJohn Foley26 Oct
  • RE: mysql is a pain in the assBob Kline26 Oct
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Re: Hardware vs Software and the speedfooler30 Oct
  • Re: Hardware vs Software and the speedsinisa30 Oct
Re: mysql is a pain in the assJoseph R. Junkin30 Oct
  • Re: mysql is a pain in the assLarry Rufo30 Oct
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  • Re: mysql is a pain in the assMike Schwartz1 Nov
Re: Hardware vs Software and the speedEd Carp1 Nov
Re: mysql is a pain in the assEd Carp1 Nov
  • Re: mysql is a pain in the assLarry Rufo2 Nov
Re: mysql is a pain in the assDejan Lekic1 Nov
Re: mysql is a pain in the assRaul Miller1 Nov
  • Re: mysql is a pain in the asssinisa2 Nov
    • Re: mysql is a pain in the assMatthias Urlichs2 Nov
    • Re: mysql is a pain in the assRaul Miller2 Nov
      • Re: mysql is a pain in the assPatrick Greenwell2 Nov
        • Re: mysql is a pain in the assRaul Miller2 Nov
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              • Re: mysql is a pain in the asssinisa4 Nov
                • Re: mysql is a pain in the assRaul Miller4 Nov
              • Re: mysql is a pain in the assMichael Widenius14 Nov
                • Re: mysql is a pain in the assRaul Miller14 Nov
      • Re: mysql is a pain in the asssinisa3 Nov
        • Re: mysql is a pain in the assRaul Miller3 Nov
          • Re: mysql is a pain in the assMichael Widenius14 Nov
  • Re: mysql is a pain in the assDave Hodgkinson2 Nov
    • Re: mysql is a pain in the assRaul Miller2 Nov
Re: mysql is a pain in the assEd Carp3 Nov
  • Re: mysql is a pain in the assRaul Miller3 Nov
    • Re: mysql is a pain in the assMike Wexler3 Nov
      • Re: mysql is a pain in the assMatthias Urlichs7 Nov
        • Re: mysql is a pain in the assRaul Miller8 Nov
        • Re: mysql is a pain in the assMichael Widenius28 Nov
      • Re: mysql is a pain in the assMichael Widenius28 Nov
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