Cassandra 2.1 features¶
Cassandra 2.1 new CQL features include:
- Nested user-defined types
- Improved counter columns that maintains the correct count when Cassandra replays the commit log
- Configurable counter cache
- Support for indexes on collections, including using map keys to filter query results
- Timestamps precise to the millisecond
- The new tuple type that holds fixed-length sets of typed positional fields
The cqlsh utility also has been improved:
Cassandra 2.0.x features¶
Cassandra 2.0.x key features are:
- Lightweight transactions using the IF keyword in INSERT and UPDATE statements.
- Prevention of application errors by performing conditional tests for the existence of a table, keyspace, or index.
- Initial support for triggers that fire events executed in or out of a database cluster.
- The ALTER TABLE DROP command, which had been removed in the earlier release.
- Column aliases, similar to aliases in RDBMS SQL, in a SELECT statement.
- Indexing of the any part, partition key or clustering columns, portion of a compound primary key.
DataStax drivers support Cassandra 2.0.
CQL for Cassandra 2.0 deprecated super columns. Cassandra continues to support apps that query super columns, translating super columns on the fly into CQL constructs and results.
Some changes were made to the cqlsh commands in CQL Cassandra 2.0:
Several CQL table attributes were added in CQL included with Cassandra 2.0: