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1

One suggestion that I saw when the new CE was announced came from Brent Ozar. You needed to test this out before you went live with 2014. Run on 2014 but with the level indicating 2012 and benchmark the times and plans. Then change to 2014 level and see which plans changed. From there you attempted to tune the bad plans. Trace flag 4199 has been around for ...


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Based on my experience with such issue and as mentioned in This Blogs.msdn article You need to apply SP1 but you must also enable trace flag 4199 in order to activate the fix.SQL Server 2014 Service Pack 1 made various fixes on new Cardinality Estimator (new CE). The release notes also documents the fixes. So I suggest to suppress regression you ...


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You could disable it on a per database level by changing the compatibility level; assuming they don't use SQL 2014 specific language features. But ultimately I think you need to determine which queries have bad execution plans and why. To do this you could capture a replay trace and start replaying it on a test bed with and without the trace flag / compat ...


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The warning does not always correspond to missing single-column statistics. There is no easy way to precisely determine the exact statistic the optimizer went looking for and did not find in all cases, but it is almost always a multi-column statistic that would provide some correlation information across multiple equality predicates in the query. Perhaps ...


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Should SQL Server not identify the highest value for that key and use that as the maximum RANGE_HI_KEY? Or is this just one of the limits of update without using FULLSCAN? It's a limitation of the current implementation of sampled statistics. As it stands, sampled statistics collection uses TABLESAMPLE SYSTEM, which uses an allocation-order scan and ...


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Quick guess: enable trace flag 4139. You are already running SP2-CU1 so this should work Note the guidelines about TF 2389 ad 2390 too and also see http://sql-sasquatch.blogspot.com.mt/2013/06/mssql-plan-guides-to-address-ascending.html (Note, I've not really hit this problem and have not dived in that deep)



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