Questions about attachment in couchbase

#1

1 How attachments store in couchbase ( not in couchbaselite)?
1 Attachment is much bigger than document, and in the most use case, document is more important than attachment.
so from store view or query optimizing view, Does separate attachment from document can make query better?
2 Can I search the documents that included attachment that created 1 year before, and remove the the attachments for save the storage space? And how?
3 If I want to search attachment by name keywords, or even by attachment body, Is there a suggest way?

#2

Can any body answer the questions?