Plan Cache Internals

Knowing when and how plans are reused or recompiled can help you design well-performing applications. The more you understand about optimal query plans, and how different actual values and cardinalities require different plans, the more you can determine when recompilation is a useful thing. When you are getting unnecessary recompiles, or when SQL Server is not recompiling when you think it should, your troubleshooting efforts will be easier the more you know about how plans are managed internally. In this section, we’ll explore the internal organization of the plan cache, the metadata available, how SQL Server finds a plan in cache, plan cache sizing, and SQL Server’s plan eviction policy.

Cache Stores

SQL Server’s plan ...

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