Cassandra 1.2 introduced several new features including:
- Concurrent schema changes and virtual nodes to improve scalability and performance.
- "Fat node" support and JBOD improvements for easier storage expansion.
- Faster compaction with off-heap bloom filters and compression metadata.
- Atomic batches for distributed transactions across data centers.
- Enhancements to the CQL query language including collections and a data dictionary.
- Request tracing for troubleshooting distributed queries.