Mean time between edits on the “Insomnia” article between 9 PM and 7 AM

SQL

USE frwiki_p;
SELECT date, COUNT(time) + 1 AS edit_count, AVG(time) AS average_interval
FROM
  (SELECT DATE(DATE_SUB(rev_timestamp, INTERVAL 10 HOUR)) AS date,
          TIMESTAMPDIFF(MINUTE, @previous, rev_timestamp) AS time,
          @previous := rev_timestamp
   FROM (SELECT @previous := 0) AS _
   JOIN revision
   JOIN page ON page_id = rev_page
   WHERE page_namespace = 0
   AND page_title = 'Insomnie'
   AND (HOUR(rev_timestamp) > 19 OR HOUR(rev_timestamp) < 5)
   ORDER BY rev_timestamp) AS deltas
WHERE time < 600
GROUP BY date;

SQL

Checking query status...