(Dab)pages without outgoing links to primary topic

SQL

with article_redirect as (
  select page_title, rd_title from page
  join redirect on page_id = rd_from
  where page_namespace = 0 and page_is_redirect = 1 and rd_namespace = 0
)

/*
select p1.page_title, p2.page_title from page p1
join page p2 on p2.page_namespace = 0 and p2.page_is_redirect = 0
and p2.page_title = substring(p1.page_title, 1, INSTR(p1.page_title, "_(disambiguation)")-1)
where p1.page_title like '%\_(disambiguation)' and p1.page_namespace = 0 and p1.page_is_redirect = 0
and not exists (
  select 1 from pagelinks where pl_from = p1.page_id
  and pl_namespace = 0 and pl_from_namespace = 0 and pl_title = p2.page_title
)
and not exists (
  select 1 from pagelinks where pl_from = p1.page_id and pl_namespace = 0 and pl_from_namespace = 0
  and pl_title in (
    select page_title from redirect, page where page_id = rd_from and rd_namespace = 0 and rd_title = p2.page_title
  )
)
*/

select p1.page_title, rd_title from page p1
/*
join page p2 on p2.page_namespace = 0 and p2.page_is_redirect = 1
and p2.page_title = substring(p1.page_title, 1, INSTR(p1.page_title, "_(disambiguation)")-1)
join redirect on rd_namespace = 0 and rd_from = p2.page_id
*/

join article_redirect ar1 on ar1.page_title = substring(p1.page_title, 1, INSTR(p1.page_title, "_(disambiguation)")-1)

where p1.page_title like '%\_(disambiguation)' and p1.page_namespace = 0 and p1.page_is_redirect = 0

and not exists (
  select 1 from pagelinks where pl_from = p1.page_id and pl_namespace = 0 and pl_from_namespace = 0
  and (pl_title in (
    select ar2.page_title from article_redirect ar2 where ar2.rd_title = ar1.rd_title
  )
  or pl_title = ar1.rd_title)
)

limit 1

/*
     or p2.page_title in (
       select rd_title from redirect, page where rd_namespace = 0 and rd_from = page_id
       and page_title = substring(p1.page_title, 1, INSTR(p1.page_title, "_(disambiguation)")-1)
     ))
*/
SQL

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