title: Using Redis for in-memory caching and DynamoDB (or Cassandra) for URL shortener
body: <p>I am a beginner programmer and am building a web service for a URL shortener, and am considering which NoSQL to use. I only need to store original urls and shortened ones, so Redis is an obvious choice as it is very fast. But Redis is limited to the memory size, whereas other key-value NoSQL like DynamoDB or Cassandra stores data in the disk. Do you think it makes sense to use Redis as a caching for heavy-read requests and use other NoSQL as a database at the same time?</p>