LEFT JOIN string_ids AS x1 ON (x1.id = extension_id_x)
    LEFT JOIN string_ids AS x2 ON (x2.id = api_name_x)
    LEFT JOIN string_ids AS x3 ON (x3.id = args_x)
    LEFT JOIN url_ids    AS x4 ON (x4.id = page_url_x)
    LEFT JOIN string_ids AS x5 ON (x5.id = page_title_x)
    LEFT JOIN url_ids    AS x6 ON (x6.id = arg_url_x)
    LEFT JOIN string_ids AS x7 ON (x7.id = other_x)