Re: Index speed - a couple of questions
Posted by:
James Day
Date: February 01, 2005 05:14PM
What you heard in 1 is correct. Your where needs to include the leading key parts or the trailing key parts in the index won't be used. Prior ot version 5 MySQL wouldn't use more than one key per table name/alias in each select statement, so combined keys would be necessary. See
http://dev.mysql.com/doc/mysql/en/index-merge-optimization.html for an enhancement in version 5.
If you're indexing individual words within a text column you'd probably want to use a fulltext index. A like clause with %someword% requires a full table scan if you don't use a fulltext index. Whether you use fulltext or normal index depends on what you're doing.
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February 01, 2005 09:11AM
Re: Index speed - a couple of questions
February 01, 2005 05:14PM
February 02, 2005 02:43AM
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