Non-relational db, which one is the right choice [closed]

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Which Non-relational database should I choose(I know the question is a subjective one and involves taking into consideration the demands of the system).

I read this article cassandra-vs-mongodb-vs-couchdb-vs-redis, but still couldn't decide.

It would be really good if the experienced guys here could throw some light on the key points to consider while making this decision.

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Every type of database is very good at something, and cannot stand against the other at something. It is impossible to say which is the best in all the fields... otherwise there would not be reasons for other to exist.

I feel sometime that choices are made on personal feelings about which one is closer to the programmer's way of thinking.

If you specify which are your requirements and your scenario, a better answer can be made.

For example MongoDB and Redis are complementary, they solve different problems and can be (and are) used together to maximize performance. No one beats cassandra on scalability, but it is not so flexible in the schema. CouchDB has an internal "application logic" which is great, but you have to change your mind and learn to speak in json.