join - log-queries-not-using-indexes and LIKE in MySQL -
i have "log-queries-not-using-indexes" enabled in mysql. have 1 query being logged mysql such i.e. query not using indexes. thing query uses e.g.
category '%fashion%'
and if remove or change to
category = 'fashion'
then says using indexes.
so when using in our query, mysql log not using indexes no matter what?
thanks
using clause %fashion%
never use regular index. need full-text index if want kind of search.
remember varchar
indexes on first part of string. so, if searching ocurrence of fashion
on any part of string, index offer no improve performance since need search every single string.
however, if search first part this:
select * table field 'fashion%'
then index used , helpful.
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