Cassandra – Alter KeySpace
Alter Keyspace command allows you to alter the replicaton factor, strategy name and durable writes attributes. Below the syntax for Alter KeySpace command.
Syntax:
Alter Keyspace KeyspaceName with replication= {'class':'StrategyName', 'replication_factor': no of replications on different nodes} with DURABLE_WRITES=true/false
Note:Using Alter command Keyspace Name cannot be changed in cassandra.
By default, DURABLE_WRITES value is true. If set to false, no updates will be written to the commit log.
Example:
cqlsh> ALTER KEYSPACE i2Tutorials WITH replication = {'class': 'NetworkTopologyStrategy', 'replication_factor' : 3}; Cqlsh> Describe keyspaces; i2tutorials system_schema system_auth system system_distributed system_traces
Validate the ALTER KeySpace
cqlsh:system_schema> SELECT * FROM system_schema.keyspaces; keyspace_name | durable_writes | replication --------------------+----------------+----------------------------------------------- I2Tutorials | True | {'class': 'org.apache.cassandra.locator.NetworkTopologyStrategy', 'replication_factor':'3'} system_auth | True | {'class': 'org.apache.cassandra.locator.SimpleStrategy', 'replication_factor':'1'} system_schema | True | {'class': 'org.apache.cassandra.locator.LocalStrategy'} system_distributed | True | {'class': 'org.apache.cassandra.locator.SimpleStrategy', 'replication_factor':'3'} system | True | {'class': 'org.apache.cassandra.locator.LocalStrategy'} system_traces | True | {'class': 'org.apache.cassandra.locator.SimpleStrategy', 'replication_factor':'2'}