Why nosql with cassandra instead of mysql?

Question

I work on large database (hundreds of GB) and Mysql now gives me more or less satisfaction. I hesitate to cassandra on launch.

What I want to know everything before,

Answer 1

Yes, you can definitely tune a MySQL to give you performance by cutting down a lot of the overheads. NoSQL cuts out the overheads by not having the feature to enable them in the first place.

The applications of NoSQL are very different from traditional SQL structure. SQLs are by default tuned for OLTP performance with normalized schema structures and the ability to have join queries etc. NoSQL on the other hand is a good fast read/write structure. A really good example would be an activity feed on twitter/facebook (I don't know if Twitter/FB use NoSQL I'm just taking an example).