Introduction to Plan Guides
Ever needed to slightly change the behavior of a query in a third party app, or maybe to adjust the plan of a stored procedure without changing code? Plan guides let you set up situation where it if a query matches a template we can add or remove OPTION hints from the query, or even specify a different plan entirely. It's not perfect, but it's an interesting approach that can get you out a jam. It can also cause a headache if you are troubleshooting and don't realize a plan guide is altering the plan you're working on.