public function engineCompat(string $sql): string
    {
        $sql = $this->c::mbTrim($sql);

        if (!preg_match('/^CREATE\s+TABLE\b/ui', $sql)) {
            return $sql; // Not applicable.
        }
        $sql = preg_replace('/\bENGINE\=[%a-z0-9_\-]*/ui', '', $sql);

        if (!preg_match('/\bFULLTEXT\s+KEY\b/ui', $sql) || version_compare($this->wp->db_version(), '5.6.4', '>=')) {
            // MySQL v5.6.4+ supports fulltext indexes w/ InnoDB. See: <http://bit.ly/ZVeF42>
            $sql = preg_replace('/;$/u', ' ENGINE=InnoDB;', $sql);
        } else {
            $sql = preg_replace('/;$/u', ' ENGINE=MyISAM;', $sql);
        }
        return $sql;
    }