Hi allI was interested to know whether many people have experienced performance issues when upgrading to 2014 (and setting compatibility level to 120), and the reasons behind those issues, as they relate to the new CE.We are in the process of upgrading and testing and have some stored procs which execute in approximately one second on 2012, yet which are taking over a minute on 2014.After faffing around with execution plans, indexes, statistics, parameter sniffing and getting nowhere, we determined that the new CE was the culprit.Interestingly, during these experiments, SSMS identified a missing index when I obtained the actual execution plan. I created that index and the execution time increased to 1 minute 50 seconds!I was able to determine that calling a scalar UDF (which validates postcodes) in a query's WHERE clause was the problem. OK, we don't like these, so I refactored that to use an iTVF instead. That took the execution time down to 20 seconds. Still not good enough.We currently have three 'solutions':1) Revert compatibility level to 1102) Use the query hint (QUERYTRACEON 9481) within those specific queries which have been hit.3) Refactor the queries – the exact method used would depend on the query being used.Have you had similar issues? How did you solve them?
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