MongoDB Single Document size limit is 16MB

Question

Known Information: Its is know that MongoDB stores in BSON (Binary JSON) and the maximum BSON document size is 16MB.

Question: Why

Answer 1

Check out the thread on the JIRA ticket that increased the value from 4MB to 16MB. There is a sizeable debate on the ticket: https://jira.mongodb.org/browse/SERVER-431

It seems to be arbitrary why they chose 16MB, and not say 32MB. It was increased because many people needed to store documents larger than 4MB (and I presume lower than 16MB). Some people have asked in that thread to have it made configurable (like you asked), which makes sense to me. Not sure why they haven't decided to do this.