CRDB and Cassandra are to totally different databases.

CockroachDB is full SQL ACID database. With transactions, consistent indexes, joins. It's also strongly consistent overall.

Cassandra is really just a key-value store, with a hierarchy of sorting keys as part of the key, so that you can do range scans with good performance (and various access patterns). Indexes are asynchronously updated (as far as I know). No transactions nor joins. Its consistency is varying (configurable).

Turns out for Cassandra to work properly you need double the storage space that you max want available, otherwise it can't vacuum properly. So if you want to be able to store 1 TB, you need 2 TB, and if you go over 1 TB, it's not guaranteed to be able to vacuum at all.

Also, Apache Cassandra and DataStax Cassandra did a hard split recently, so the docs are no longer in sync, making it a lot harder to search for stuff if you're using Apache Cassandra.

Also, patch versions of Cassandra are not guaranteed to be binary compatible (sstables), [so upgrading from 3.0.5 to 3.0.9](https://gist.github.com/shyamsalimkumar/49a61e5bc6f403d20c55...)? Expect a long migration.