Number of lonely items per group of 250000 QIDs

SQL

-- https://www.mediawiki.org/wiki/Manual:Database_layout
-- note: the page table does not contain Q-IDs that have been deleted (or never been created)

-- number of redirects: use WQS
-- number of empty items: use WQS

-- total number of item in bin: (rest may have been deleted, or never created)
SELECT
	CEILING(SUBSTRING(page_title FROM 2) / 250000) AS bin,
    COUNT(*) AS cnt
FROM page
WHERE page_namespace=0
GROUP BY bin
ORDER BY bin ASC;

SELECT
	CEILING(ips_item_id / 250000) AS bin,
    COUNT(*) AS cnt
FROM (SELECT ips_site_id, ips_item_id FROM wb_items_per_site GROUP BY ips_item_id HAVING COUNT(*)=1) items
GROUP BY bin
ORDER BY bin ASC;

SELECT
	CEILING(ips_item_id / 250000) AS bin,
    COUNT(*) AS cnt
FROM (SELECT ips_site_id, ips_item_id FROM wb_items_per_site GROUP BY ips_item_id HAVING COUNT(*)>1) items
GROUP BY bin
ORDER BY bin ASC;

SELECT
	ips_site_id,
    COUNT(*) AS cnt
FROM (SELECT ips_site_id, ips_item_id FROM wb_items_per_site GROUP BY ips_item_id HAVING COUNT(*)=1) items
GROUP BY ips_site_id
ORDER BY cnt DESC;

-- number of items that have been deleted once (regardless of whether they have been restored):
-- SELECT DISTINCT log_title FROM logging WHERE log_namespace=0 AND log_type='delete'

-- pages that have been deleted, and not been restored
-- SELECT DISTINCT log_title FROM logging WHERE log_namespace=0 AND log_type='delete' AND log_title NOT IN (SELECT page_title FROM page WHERE page_namespace=0)
-- SELECT CEILING(SUBSTRING(log_title FROM 2) / 100000) AS bin, COUNT(*) AS cnt FROM logging WHERE log_namespace=0 AND log_type='delete' AND log_title NOT IN (SELECT page_title FROM page WHERE page_namespace=0)

-- SELECT ?bin (COUNT(*) AS ?cnt) WHERE {
--   #?item wikibase:statements 0 .
--   #?item owl:sameAs [] .
--   ?item wikibase:sitelinks [] .
--   BIND(ceil(xsd:integer(SUBSTR(STR(?item),33)) / 100000) AS ?bin) .
-- } GROUP BY ?bin ORDER BY ASC(?bin)
SQL

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