USE commonswiki_p;

​

  SELECT page_title

  FROM page

  INNER JOIN categorylinks

  ON cl_from = page_id

  WHERE cl_type = "page"

  AND page_namespace = 2

  AND cl_to IN (

    SELECT * FROM (

      SELECT 'Users_suspected_of_abusing_Wikipedia_Zero' AS catname

      UNION

      SELECT page_title AS catname

      FROM page

      INNER JOIN categorylinks

      ON cl_from = page_id

      WHERE cl_type = 'subcat'

      AND cl_to = 'Users_suspected_of_abusing_Wikipedia_Zero'

    ) wp0cats /* Using MATERIALIZED per https://stackoverflow.com/a/6157797 */

  )