There’s no such thing as a schemaless database. I know, lots of people want a schemaless database, and lots of companies are promoting their products as schemaless DBMSs. And schemaless DBMSs exist. But schemaless databases are mythical beasts because there is always a schema somewhere. Usually in multiple places, which I will later claim is what causes grief.
There Is Always A Schema We should define “schema” first. It comes from Greek roots, meaning “form, figure” according to my dictionary.