The query might still work depending on where these chars are placed,
but it seems weird to only remove *some* of the valid chars here.
See https://dev.mysql.com/doc/refman/5.6/en/fulltext-boolean.html
Note that the query runs both the actual boolean query with chars,
and then a separate relevance search without them.
This came up in https://github.com/silverstripe/silverstripe-cms/issues/1452, and wasn't fully addressed.
Either we allow boolean mode and all the constraints this brings around special character usage,
or we filter out those special characters, which makes boolean mode pointless.
You can't just pass arbitrary user input in a power-user function like this.
See https://dev.mysql.com/doc/refman/5.6/en/fulltext-boolean.html
Context: This used to work for some examples like "foo>*" under MyISAM,
presumably because it had a more lenient parser. InnoDB rightfully complains about this now.
clearTable is mainly used for clearing data between tests. In this case,
there are very few or zero records, and DELETE FROM is quicker than
TRUNCATE, which works by deleting and recreating the table.
This materially speeds up test execution, at least on MySQL.
Cherry-pick of SS3 ae9ab22a8f
