Can someone explain to me what NoSQL equivalents are for concepts like primary key and general data consistency? My other question is that I've read several pl

Can someone explain to me what NoSQL equivalents are for concepts like primary key and general data consistency? My other question is that I've read several places that NoSQL makes most sense for full-text documents. And yet I see company after company with little apparent full-text data boasting about their NoSQL use. I am especially aware of this as someone in the job market seeing terms like Hadoop and MongoDB just thrown around in the job description. How? Why?