Qualified titles with shared base name lacking a (disambiguation) page

SQL

SELECT SUBSTRING_INDEX(page_title, "_(", 1) AS basename,
 SUM(1 - page_is_redirect) pages, GROUP_CONCAT(page_title ORDER BY page_title SEPARATOR'|') AS titles
FROM page Pq
WHERE page_namespace = 0 AND page_title < "K" AND page_title NOT REGEXP "_\\((season|series|\\d{4}(.\\d{4})?\\))|\\)."
AND (NOT EXISTS (SELECT 1 FROM page Pb /* basename links to qualified name */
                 JOIN pagelinks ON pl_from = Pb.page_id AND pl_namespace = 0 AND pl_title = Pq.page_title
                 WHERE Pb.page_namespace = 0 AND Pb.page_title = SUBSTRING_INDEX(Pq.page_title, "_(", 1) AND Pb.page_title != Pq.page_title)
 AND NOT EXISTS (SELECT 1 FROM page Pb /* qualified name is a redirect, and basename links to its target */
                 JOIN redirect ON rd_from = Pq.page_id AND rd_namespace = 0
                 JOIN pagelinks ON pl_from = Pb.page_id AND pl_namespace = 0 AND pl_title = rd_title
                 WHERE Pb.page_namespace = 0 AND Pb.page_title = SUBSTRING_INDEX(Pq.page_title, "_(", 1) AND Pb.page_title != Pq.page_title
                 AND Pq.page_is_redirect = 1)
 AND NOT EXISTS (SELECT 1 FROM page Pb /* basename links to redirect to qualified name */
                 JOIN pagelinks ON pl_from = Pb.page_id AND pl_namespace = 0
                 JOIN page Pr ON Pr.page_namespace = 0 AND Pr.page_title = pl_title
                 JOIN redirect ON rd_from = Pr.page_id  AND rd_namespace = 0 AND rd_title = Pq.page_title
                 WHERE Pb.page_namespace = 0 AND Pb.page_title = SUBSTRING_INDEX(Pq.page_title, "_(", 1) AND Pb.page_title != Pq.page_title)
 AND NOT EXISTS (SELECT 1 FROM page Pb /* qualified name is a redirect, and basename links to another redirect to its target */
                 JOIN redirect Rq ON Rq.rd_from = Pq.page_id AND Rq.rd_namespace = 0
                 JOIN pagelinks ON pl_from = Pb.page_id AND pl_namespace = 0
                 JOIN page Pr ON Pr.page_namespace = 0 AND Pr.page_title = pl_title
                 JOIN redirect Rb ON Rb.rd_from = Pr.page_id AND Rb.rd_namespace = 0 AND Rb.rd_title = Rq.rd_title
                 WHERE Pb.page_namespace = 0 AND Pb.page_title = SUBSTRING_INDEX(Pq.page_title, "_(", 1) AND Pb.page_title != Pq.page_title
                 AND Pq.page_is_redirect = 1)
 AND NOT EXISTS (SELECT 1 FROM redirect /* qualified name redirects to basename */
                 JOIN page Pb ON Pb.page_namespace = 0 AND Pb.page_title = rd_title AND Pb.page_title = SUBSTRING_INDEX(Pq.page_title, "_(", 1)
                 WHERE rd_from = Pq.page_id AND rd_namespace = 0)
 OR page_title LIKE "%_(disambiguation)")
GROUP BY basename
HAVING pages >= 5
AND MAX(CASE WHEN page_title LIKE "%_(disambiguation)" THEN 1 ELSE 0 END) = 0
AND MAX(CASE WHEN page_title = basename AND page_is_redirect = 1 THEN 1 ELSE 0 END) = 0
ORDER BY basename
SQL

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