public C bigResult() {
        return addFlag(Position.AFTER_SELECT, SQL_BIG_RESULT);
    }
For SQL_BIG_RESULT, MySQL directly uses disk-based temporary tables if needed, and prefers
sorting to using a temporary table with a key on the GROUP BY elements.

@return the current object
querydsl-sql/src/main/java/com/querydsl/sql/mysql/AbstractMySQLQuery.java