instruction: Average answer length per user > 3K rep..
response: SELECT u.Id AS "user_link", COUNT(*) AS "answer_count", MIN(LENGTH(p.Body)) AS "min", AVG(LENGTH(p.Body)) AS "average", MAX(LENGTH(p.Body)) AS "max", VAR(LENGTH(p.Body)) AS "variance", STDEV(LENGTH(p.Body)) AS "stdev" FROM Users AS u, Posts AS p WHERE p.OwnerUserId = u.Id AND p.PostTypeId = 2 AND u.Reputation > 3000 /* AND (SELECT Count(*) FROM Posts q WHERE q.OwnerUserId = u.Id AND p.PostTypeId = 2 GROUP BY q.OwnerUserId) >= 10 */ GROUP BY u.Id ORDER BY 'average'