MongoDB: Trade-offs of dropping a collection vs. removing all of its documents

Question

What are the trade-offs of dropping a MongoDB collection vs. removing all of its documents (assuming the collection will be re-created immediately)?

Answer 1

If you go through a remove all the documents from a collection, then you'll be doing a lot more work (freeing the document's storage, clearing the index entries that point to the document, and so on). If you instead just drop the collection, it'll just be reclaiming the extents that the collection and its indexes use.

One other difference is that dropping the collection will also remove the collection's indexes.