public function purge()
    {
        $this->dbHandler->beginTransaction();
        $query = $this->dbHandler->createDeleteQuery();
        $tables = [
            'ezsearch_object_word_link',
            'ezsearch_search_phrase',
            'ezsearch_word',
        ];
        foreach ($tables as $tbl) {
            $query->deleteFrom($tbl);
            $stmt = $query->prepare();
            $stmt->execute();
        }
        $this->dbHandler->commit();
    }