A relational database is like a garage that forces you to take your car apart and store the pieces in little drawers
—Object-oriented data community, mid-1990s
An Object database is like a closet which requires that you hang up your suit with tie, underwear, belt, socks and shoes all attached.
—David Ensor, same period
A document database is a nonrelational database that stores data as structured documents, usually in XML or JSON formats. The “document database” definition doesn’t imply anything specific beyond the document storage model: document databases are free to implement ACID transactions or other characteristics ...