MariaDB FULLTEXT search with short / mandatory words

Just checking I'm understanding this correctly: CREATE TABLE customer ( id INT NOT NULL AUTO_INCREMENT, name TINYTEXT NOT NULL, PRIMARY KEY (id), FULLTEXT (name) ) ENGINE = InnoDB; INSERT INTO customer VALUES (1, "ABC.DEF"); INSERT INTO customer VALUES (2, "ABC_DEF"); INSERT INTO customer VALUES (3, "ABC'DEF"); INSERT INTO customer VALUES (4, "ABC.DE"); INSERT INTO customer VALUES (5, "ABC.DFF"); Where I've got innodb_ft_min_token_size set to 3 (default is 4). --- When running: SELECT c.*, MATCH (name) AGAINST ("+ABC +DEF" IN BOOLEAN MODE) AS m FROM customer AS c Customers 1 and 3 match, because the . and ' are seen as word separators ([annoying for O'Brien](https://dba.stackexchange.com/q/250524)) . For customer 2, because the underscore gets the whole name treated as a single word, the "DEF" word cannot be found. --- If I change the MATCH to "+ABC +DE". 1, 2, or 3 do not match because this is using a full word match ("+DE" does not match "DEF"). 4 does not match because... innodb_ft_min_token_size is set to 3? As in, the 2 letter "DE" word is not in the FULLTEXT INDEX? --- If I change the MATCH to use asterisks (e.g. "+ABC* +DE*"), that will use *prefix* matching. But will only add customers 1 and 3 to the selection. Because the 2 letter "DE" word for customer 4 is not in the FULLTEXT INDEX? --- If I change the MATCH to use "+ABC.DE*", it matches all of them. Note how they all get the same rank (even customer 5), and this is no different to "+ABC*", where MATCH seems to be seeing the "DE*" as a separate word, and not matching it against anything. Whereas "+ABC DE*" is explicitly keeping it as a separate word, and the scores are handled appropriately. --- While the individual points make sense, I'm not sure this creates a good system. For a bit more consistency, I'm wondering if the database should ignore short words (tokens) in the MATCH query, in the same way it does when building the FULLTEXT INDEX. Only because I don't think "+DE" will ever do anything useful when the min token size is 3; and it's not exactly easy for the developer to identify what the individual words in the FULLTEXT INDEX will be (i.e. to remove them).