Explain plans are the basis for both understanding and tuning query performance in MongoDB. They contain all of the information one could ever need when performing that task such as the enumerated plans, execution metrics, index bounds, and much (much) more. But translating that data into optimized query performance can feel like a daunting task that is reserved for experts.

This intermediate-level talk, based on my years of experience tuning MongoDB queries as a member of the global support …