Trying To Force A Plan For A Different Query With Query Store

Erin Stellato shows us that you cannot use a plan generated for one query as a forced plan for a different query in Query Store:

This is question I’ve gotten a few times in class…Can you force a plan for a different query with Query Store?

tl;dr

No.

Assume you have two similar queries, but they have different query_id values in Query Store.  One of the queries has a plan that’s stable, and I want to force that plan for the other query.  Query Store provides no ability to do this in the UI, but you can try it with the stored procedure.  Let’s take a look…

I can see the potential benefit, but the downside risk is huge, so it makes sense not to allow this.

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