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 organization, will demonstrate to you that anybody can read and interpret an explain plan.

During the talk we will discuss some fundamental concepts powering the optimizer, we will discover the hidden gems that are buried as key metrics in explain plans, and I will share with you the secret navigation tricks that we use to read explain plan treasure maps. Together, we will find where X marks the spot to reveal a bounty of performant queries … Arr, Matey!