Microsoft SQL Server 2014 Unleashed

Validating Plan Guides

The new system function sys.fn_validate_plan_guide can be used to validate a plan guide. Plan guides can become invalid after changes such as dropping an index are made to the database. By validating a plan guide, you can determine whether the plan guide can be used unmodified by the query optimizer. The sys.fn_validate_plan_guide function returns the first error message encountered when the plan guide is applied to its query. If the plan guide is valid, an empty rowset is returned.