What is the fastest document-oriented database?

Question

NoSQL

Tell me the fastest and most compact database for a highly loaded service, a document-oriented database.
If possible, then embedded

Answer 1

loosely coupled data, such as news - a brief description of the news is more accurate

In general, if you need complex selections and several different indexes - take Monga, if there are only one key selections - look at key-value: if you need main storage (i.e. NOT for cache), then try Riak, if for caching what - something that is already in some other (main) database, then Redis is a good fit.