This question is necessarily vague, and I apologize in advanced for that. Somewhere on this stackexchange I saw an answer that referred to using third-party applications that can split a large content database (3TB in my case) into multiple smaller files. The context led me to believe this was something on the SQL side rather than SharePoint side, and the closest I've been able to find is file-groups and file splitting, both of which I find somewhat confusing. This question may be closed for being too broad, but I figured it was worth a shot.
Is there a third-party application or SQL functionality that can break a single content database into multiple MDF files, similar in nature to a ZIP file?
The bulk of the content cannot be moved into a separate site collection, so that is not an option.