Querying a system table 

Details about Cassandra database objects and cluster configuration in the system keyspace tables.

The system keyspace includes a number of tables that contain details about your Cassandra database objects and cluster configuration.

Cassandra populates these tables and others in the system keyspace.
Columns in System Tables
Table name Column name Comment
schema_keyspaces keyspace_name, durable_writes, strategy_class, strategy_options None
local "key", bootstrapped, cluster_name, cql_version, data_center, gossip_generation, native_protocol_version,partitioner, rack, release_version, ring_id, schema_version, thrift_version, tokens set, truncated at map Information a node has about itself and a superset of gossip.
peers peer, data_center, rack, release_version, ring_id, rpc_address, schema_version, tokens Each node records what other nodes tell it about themselves over the gossip.
schema_columns keyspace_name, columnfamily_name, column_name, component_index, index_name, index_options, index_type, validator Used internally with compound primary keys.
schema_columnfamilies See comment. Inspect schema_columnfamilies to get detailed information about specific tables.