- no big difference for insert and update
- So, separate collections are good if you need to select individual documents, need more control over querying, or have huge documents.
Embedded documents are good when you want the entire document, the document with a $slice of comments, or with no comments at all.
- As a general rule, if you have a lot of “comments” or if they are large, a separate collection might be best.
Smaller and/or fewer documents tend to be a natural fit for embedding.