Q&A for network engineers
select p1.OwnerUserId, p2.OwnerUserId, Count(1) FROM PostTags, Posts p1, Posts p2 WHERE PostTags.TagId = 1386 AND PostTags.PostId = p1.Id AND p1.CreationDate >= '2012-01-01' AND p2.ParentId = p1.Id AND p1.PostTypeId <= 2 AND p2.PostTypeId <= 2 GROUP BY p1.OwnerUserId, p2.OwnerUserId