Use Case

We support the following explain APIs for cursors:

collection.find().explain();
collection.aggregate().explain();

collection.find({}, { explain: ... }))
collection.aggregate({}, { explain: ... }))

The latter two are strange - `find` and `aggregate` always return cursors, even when explain is specified. As a result, to use these APIs, you must iterate the cursor:

const [explainResult] = collection.find({}, { explain: ... })).toArray();
// or
const explainResult = collection.find({}, { explain: ... })).next();

This API requires special workarounds in our cursors but provides little value. We should drop support for this API.

These APIs will be removed in favor of:

collection.find().explain();
collection.aggregate().explain();

User Experience

• What is the desired/expected outcome for the user once this ticket is implemented?
• If bug: What is the number of impacted customers? How severe is the impact? Is anyone blocked or broken?

Dependencies

• upstream and/or downstream requirements and timelines to bear in mind

Risks/Unknowns

• What could go wrong while implementing this change? (e.g., performance, inadvertent behavioral changes in adjacent functionality, existing tech debt, etc)
• Is there an opportunity for better cross-driver alignment or testing in this area?
• Is there an opportunity to improve existing documentation on this subject?

Acceptance Criteria

Implementation Requirements

• functional reqs, potential snafus to avoid, performance targets, etc

Testing Requirements

• unit test, spec test sync, etc

Documentation Requirements

• DOCSP ticket, API docs, etc

Follow Up Requirements

• additional tickets to file, required releases, etc
• if node behavior differs/will differ from other drivers, confirm with dbx devs what standard to aim for and what plan, if any, exists to reconcile the diverging behavior moving forward