Will changing ft_min_word_len work for new indexes without breaking old ones?

MySQL & MariaDB
1

Hello.

I have tons of myisam indexes with ft_min_word_len=4. Now I want to change it to other value, like 3 but without rebuilding old indexes. For old indexes =4 is simply ok.

Will such change be ok from mysql/mariadb point of view and everything will work just fine? I mean old indexes would behave like ft_min_word_len=4 while new (or rebuilt) indexes will behave as ft_min_word_len=2?

Documentation doesn’t really cover that. It only mentions that " FULLTEXT indexes on MyISAM tables must be rebuilt after changing this variable" which would be make sense if anyone would want to new setting to work for existing indexes but that isn’t my case.

2

Hello @Arek,

  1. Why are you still on MyISAM? This is a dead engine. InnoDB supports FULLTEXT indexes.
  2. If you change this parameter, I’m not sure of the behavior when you insert/update data in those older tables. I imagine you’d be in a situation where all of the old data used min-word=4, but any new data to the tables would be constructed using min-word=2.
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3
  1. That’s existing server used by various people and I don’t control its contents.
  2. That would be probably ok if it works that way.
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4

I invite you to test this out and post your findings here.

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