I recently visited http://cassandra.apache.org/doc/cql3/CQL.html#CQLSyntax and just read this:
[...] please note that as such, they do not refer to the concept of rows and columns found in the internal implementation of Cassandra and in the thrift and CQL v2 API.
If we assume that I've understood Cassandras data model (column family, etc.) I do not understand where CQL3 differs from? Is the table model of CQL3 related to Cassandras Column Family however? I mean, how about perfomance issues? How is the CQL3 implementation compared to the relational tables?
What is the internal implementation and/or concept of CQL3's row-and-column-model? I know that there is something like Composite Column model. Is this the difference to the classical Cassandra row-column-model? Moreover I am interested in theoretical details.
Asking these questions: What did I not understand?
Unfortunately I just started getting deeper into CQL. But I am very familiar with the cassandra-cli and (my)SQL.
This should be your one-stop-shopee to learn CQL data model:
http://www.datastax.com/dev/blog/cql3-for-cassandra-experts