SQL should be fine with sharding. Evernote has actually a great article on how they sped up their sync by rethinking the sharding. http://blog.evernote.com/tech

SQL should be fine with sharding. Evernote has actually a great article on how they sped up their sync by rethinking the sharding. http://blog.evernote.com/tech/2014/01/28/synchronization-speedupification/ http://blog.evernote.com/tech/2014/01/28/synchronization-spe...