Enabling Fuzzy Matching and Stemming

The following example enables stemming and fuzzy matching for English. The preference STEM_FUZZY_PREF sets the number of expansions to the maximum allowed. This preference also instructs the system to create a substring index to improve the performance of double-truncated searches.

begin
  ctx_ddl.create_preference('STEM_FUZZY_PREF', 'BASIC_WORDLIST');
  ctx_ddl.set_attribute('STEM_FUZZY_PREF','FUZZY_MATCH','ENGLISH');
  ctx_ddl.set_attribute('STEM_FUZZY_PREF','FUZZY_SCORE','1');
  ctx_ddl.set_attribute('STEM_FUZZY_PREF','FUZZY_NUMRESULTS','5000');
  ctx_ddl.set_attribute('STEM_FUZZY_PREF','SUBSTRING_INDEX','TRUE');
  ctx_ddl.set_attribute('STEM_FUZZY_PREF','STEMMER','ENGLISH');
end;

To create the index in SQL, enter the following statement:

create index fuzzy_stem_subst_idx on mytable ( docs )
  indextype is ctxsys.context parameters ('Wordlist STEM_FUZZY_PREF');