Cassandra published its technical limitations but did not mention the max number of columns allowed. Is there a maximum number of columns? I have a need to store 400+ fields. Is this possible in Cassandra?
The maximum number of columns per row (or a set of rows, which is called "partition" in Cassandra's CQL) is 2 billion (but the partition must also fit on a physical node, see docs).
400+ fields is not a problem.