5.If your workload is running with database compatibility level 110 and you want to test or run a specific query with the new cardinality estimator, you can run the query with trace flag 2312 to use version 120 (the new version) of the cardinality estimator. To run a query with a trace flag, see the KB article Enable plan-affecting SQL Server query optimizer behavior that can be controlled by different trace flags on a specific-query level.