there is a different cluster with atlas databases (ie. not the same database exactly).
In our video lectures we have used 100YWeather dataset which has 33,382,366 documents. However, the dataset that we have in our class atlas cluster is 100YWeatherSmall which has only 250,000 documents.
All the labs, quizzes and final exam question which works with this dataset uses the 100YWeatherSmall dataset.
Hope it helps!
If you have any other query then please feel free to get back to us.
Curriculum Support Engineer