title: Cloud based NoSQL database service for sensor data
body: <p>We are new to NoSQL and now are starting on a project that aims to record sensor data from many different sensors, each recording a timestamp - value pair, into a cloud based database. The amount of sensors should scale, so the solution should be able handle the sizes of hundreds of millions or possibly even billion(s) writes a year.</p>
  
  <p>Each sensor has its own table with key(timestamp) - value and sensor metadata is in its own table.</p>
  
  <p>The system should support search functions such as the most recent values (fast data retrieval) of certain sensor types  and values from time frame of sensors in certain areas (from metadata).</p>
  
  <p>So the question is which cloud database service would be most suited to our needs?</p>
  
  <p>Thanks in advance.</p>