Apache Cassandra system_schema Keyspace

The system_schema keyspace

Cassandra maintains a predefined keyspace "system_schema" to store metadata information about keyspaces, tables, columns, views, etc. The following screenshot demonstrates DESCRIBE KEYSPACES lists of all keyspaces in the cluster, including system_schema keyspace. The DESC TABLES statement for system_schema keyspace displays tables in the keyspace. Some key tables in the system_schema keyspace include:

• keyspaces: Stores metadata about all keyspaces.

• tables: Contains information about all tables.

• columns: Contains metadata about all columns for each table.

• indexes: Contains metadata about indexes on tables.

• triggers: Stores information about triggers associated with tables.

• views: Lists materialized views associated with tables.

These tables store information about the database’s schema structure.