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Keyspaces

Setting the Keyspace at Connection Time

A session can be initially connected using a supplied keyspace.

Performance Tip: An application should create a single session object per keyspace as a session object is designed to be created once, reused, and shared by multiple threads within the application.

CassSession* session = cass_session_new();
CassCluster* cluster = cass_cluster_new();

/* Configure cluster */

CassFuture* connect_future
  = cass_session_connect_keyspace(session, cluster, "keyspace1");

/* Handle connect future */

cass_future_free(connect_future);

cass_session_free(session);
cass_cluster_free(cluster);

Changing Keyspaces

You can specify a keyspace to change to by executing a USE statement on a connection session object.

void use_keyspace(CassSession* session) {
  CassStatement* use_statement
    = cass_statement_new("USE keyspace1", 0);

  CassFuture* use_future
    = cass_session_execute(session, use_statement);

  /* Check future result... */

  cass_statement_free(use_statement);
  cass_future_free(use_future);
}

Be very careful though: if the session is shared by multiple threads, switching the keyspace at runtime could easily cause unexpected query failures.

Single Session and Multiple Keyspaces

It is possible to interact with multiple keyspaces using a single session object by fully qualifying the table names in your queries e.g. keyspace_name.table_name.

Examples

SELECT * FROM keyspace_name.table_name WHERE ...;
INSERT INTO keyspace_name.table_name (...) VALUES (...);

Creating Keyspaces and Tables

It is also possible to create keyspaces and tables by executing CQL using a session object.

Examples

CREATE KEYSPACE cpp_driver
  WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 };
CREATE TABLE cpp_driver.contributers (
  lastname text,
  firstname test,
  company text,
  website text,
  since timestamp,
  last_activity timestamp
  PRIMARY KEY(lastname));