BASIC_WORDLIST Example: Enabling Substring and Prefix Indexing

C.6 BASIC_WORDLIST Example: Enabling Substring and Prefix Indexing

This example improves performance for wildcard queries by setting the wordlist preference for prefix and substring indexing. For prefix indexing, the example creates token prefixes between three and four characters long.

begin 
ctx_ddl.create_preference('mywordlist', 'BASIC_WORDLIST'); 
ctx_ddl.set_attribute('mywordlist','PREFIX_INDEX','TRUE');
ctx_ddl.set_attribute('mywordlist','PREFIX_MIN_LENGTH', '3');
ctx_ddl.set_attribute('mywordlist','PREFIX_MAX_LENGTH', '4');
ctx_ddl.set_attribute('mywordlist','SUBSTRING_INDEX', 'YES');
end;