The Apache Cassandra database is the right choice when you need scalability and high availability without compromising performance. Linear scalability and proven fault-tolerance on commodity hardware or cloud infrastructure make it the perfect platform for mission-critical data. Cassandra's support for replicating across multiple datacenters is best-in-class, providing lower latency for your users and the peace of mind of knowing that you can survive regional outages.
In '.vimrc Setup' section, in place of this:
"" only show completion as a list instead of a sub-window
"" no preview window after completion
For more options, check: https://github.com/Valloric/YouCompleteMe#options