Archived extensions with subpages needing cleanup

SQL

select
  page_title
from
  categorylinks
  join page on page_id = cl_from
where
  cl_to = "Archived_extensions"
  and exists (
    select
      1
    from
      page subpage
    where
      subpage.page_namespace = page.page_namespace
      and subpage.page_title like concat(page.page_title, "/%")
      and not exists (
        select
          1
        from
          categorylinks
        where
          cl_from = subpage.page_id
          and cl_to = "Archived_extensions"
      )
      and not exists (
        select
          1
        from
          categorylinks
        where
          cl_from = subpage.page_id
          and cl_to = replace(
            subpage.page_title,
            page.page_title,
            "Archived_extensions"
          )
      )
  )
SQL

Checking query status...
