assisted by JNK http://stackoverflow.com/questions/5001393/query-for-fastest-growing-tags-in-data-explorer/5004684#5004684
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-- QUERY: tags with highest increase in growth, over 3 months -- assisted by JNK http://stackoverflow.com/questions/5001393/query-for-fastest-growing-tags-in-data-explorer/5004684#5004684 DECLARE @tag nvarchar(25) = ##tag:string## select tags.tagname, count(*) AS tagcount INTO #TagCountTemp1 from Posts INNER JOIN PostTags ON PostTags.PostId = Posts.id INNER JOIN Tags ON Tags.id = PostTags.TagId where datepart(year, Posts.CreationDate) = 2010 and datepart(month, Posts.CreationDate) = 11 and tags.tagname = @tag group by tags.tagname select tags.tagname, count(*) AS tagcount INTO #TagCountTemp2 from Posts INNER JOIN PostTags ON PostTags.PostId = Posts.id INNER JOIN Tags ON Tags.id = PostTags.TagId where datepart(year, Posts.CreationDate) = 2010 and datepart(month, Posts.CreationDate) = 12 and tags.tagname = @tag group by tags.tagname select tags.tagname, count(*) AS tagcount INTO #TagCountTemp3 from Posts INNER JOIN PostTags ON PostTags.PostId = Posts.id INNER JOIN Tags ON Tags.id = PostTags.TagId where datepart(year, Posts.CreationDate) = 2011 and datepart(month, Posts.CreationDate) = 1 and tags.tagname = @tag group by tags.tagname SELECT TOP 20 @tag as 'tag', t1.tagcount as 'Mon1', t2.tagcount as 'Mon2', t3.tagcount as 'Mon3', t2.tagcount-t1.tagcount as IncA, t3.tagcount-t2.tagcount as IncB, 100*(t2.tagcount-t1.tagcount)/t1.tagcount as '%a', 100*(t3.tagcount-t2.tagcount)/t2.tagcount as '%b', (100*(t3.tagcount-t2.tagcount)/t2.tagcount - 100*(t2.tagcount-t1.tagcount)/t1.tagcount) as 'diff' FROM #TagCountTemp1 as t1 LEFT JOIN #TagCountTemp2 as t2 ON t1.tagname = t2.tagname LEFT JOIN #TagCountTemp3 as t3 ON t1.tagname = t3.tagname ORDER BY diff desc