Mongodb Object.bsonsize()?

Question

MongoDB

If you use Object.bsonsize() for large documents, for example, 4 megabytes,
After all, as I understand it, with Object.bsonsize(), the entire document is read in order to then calculate its size
. Wouldn't it be faster to increment the number of bytes for this document in a separate table?

Answer 1

Irrelevant because an increment needs a base, and the base is just reading and calculating the length of the document.