Fine-Tuning MySQL Full-Text Search Most full-text variables described in this section must be set at server startup time. A server restart is required to change them; they cannot be modified while the server is running. Some variable changes require that you rebuild the  FULLTEXT  indexes in your tables. Instructions for doing so are given later in this section. •Configuring Minimum and Maximum Word Length •Configuring the Natural Language Search Threshold •Modifying Boolean Full-Text Search Operators •Character Set Modifications •Rebuilding InnoDB Full-Text Indexes •Optimizing InnoDB Full-Text Indexes •Rebuilding MyISAM Full-Text Indexes Configuring Minimum and Maximum Word Length The minimum and maximum lengths of words to be indexed are defined by the innodb_ft_min_token_size  and  innodb_ft_max_token_size  for  InnoDB  search indexes, and ft_min_word_len  and  ft_max_word_len  for  MyISAM  ones. Minimum and maximum word length full-text parameters do not apply to  FULLTEXT indexes created using the ngram parser. ngram token size is defined by the ngram_token_size  option. Note After changing any of these options, rebuild your  FULLTEXT  indexes for the change to take effect. For example, to make two-character words searchable, you could put the following lines in an option file: [mysqld] innodb_ft_min_token_size=2 ft_min_word_len=2 #define GWS_IN_USE GWS_PROB Configuring the Natural Language Search Threshold Then restart the server and rebuild your  FULLTEXT  indexes. For  MyISAM  tables, note the remarks regarding  myisamchk  in the instructions that follow for rebuilding  MyISAM  full-text indexes. For  MyISAM  search indexes, the 50% threshold for natural language searches is determined by the particular weighting scheme chosen. To disable it, look for the following line in  storage/myisam/ ftdefs.h : Change that line to this: #define GWS_IN_USE GWS_FREQ Then recompile MySQL. There is no need to rebuild the indexes in this case. By making this change, you  severely  decrease MySQL’s ability to provide adequate relevance values for the  MATCH()  function. If you really need to search for such 2219 Note