When your playground results in a find or aggregate cursor we now open the results in the new data browser so that you can paginate through the results, set a number of results per page, etc.

But we don't calculate the count yet. It is always null.

We could try some kind of best-effort way with a timeout like we do in Compass and then just fall back to null if that fails.

Consequently you can't know how many results your query matched or how many pages of results there are. So a user can also paginate "off" the end of the results and get empty pages.

I left it out initially just because of time.

This ticket is for a best-effort solution like in Compass. Rather time out or give up early and return null than leave slow and expensive operations running.