This project is just getting started so we don't have a ton of details yet, but there's going to be a big shakeup to explain and it will possibly impact the explain helper APIs. We're aiming to only do so in an additive way for request format but the response format will change dramatically.

Summary

The revamp of the query optimizer will necessitate changes to the explain output. This project aims to describe and implement those changes.

Motivation

The new optimizer will broadly still produce a winning plan, rejected plans, and executionStats. It will not produce something resembling "allPlansExecution" output. It will also use new stage names and different building blocks. Building upon some of the work done in https://jira.mongodb.org/browse/PM-1829, this project will come up with a plan to revamp the explain output and maximize comprehensibility of the new optimizer.

Notably, this project is also needed to ensure we can write integration tests of the new optimizer which stress plan selection and the details of generated plans such as index bounds.

Cast of Characters

• Product Owner: Christopher Harris
• Project Lead: Charlie Swanson
• Program Manager: Joe Kanaan
• Drivers Contact:

Documentation

Product Description
Scope Document
Syntax Document
Technical Design Document