There is a dark side to most of the current NoSQL databases, Stephan Schmidt writes. People rarely talk about it. They talk about performance, about how easy schemaless databases are to use. About nice APIs. They are mostly developers and not operation and system administrators. No-one asks those. But it’s there where rubber hits the road.

The three problems no-one talks about:

• ad hoc data fixing – either no query language available or no skills
• ad hoc reporting – either no query language available or no in-house skills
• data export – sometimes no API way to access all data