Validate Plan Guides After Upgrade
We recommend re-evaluating and testing plan guide definitions when you upgrade your application to a new release of SQL Server. Performance tuning requirements and plan guide matching behavior may change. Although an invalid plan guide will not cause a query to fail, the plan is compiled without using the plan guide and may not be the best choice. After upgrading a database to SQL Server 2014, we recommend that you perform the following tasks:
Validate existing plan guides by using the sys.fn_validate_plan_guide function.
Use extended events to monitor for misguided plans for some period of time by using the Plan Guide Unsuccessful event.