How to Alter Keyspace in Cassandra by using CQL - Cassandra / CQL Tutorial

How to Alter Keyspace in Cassandra by using CQL

To create the Keyspace in Cassandra Query Language we use "Create Keyspace Keyspace_Name with options". To Alter existing Keyspace in Cassandra , we can use "Alter Keyspace Keyspace_Name with Options".
Let's say we have created TechBrothersTutorials keyspace by using below script.

CQLSH:techbrotherstutorials> CREATE keyspace techbrotherstutorials 

WITH REPLICATION = {'class': 'NetworkTopologyStrategy', 'DC1' : 2, 'DC2' : 1}
AND durable_writes = false;

Let's check if TechbrothersTutorial Keyspace is created successfully.

CQLSH:techbrotherstutorials>SELECT * FROM   system_schema.keyspaces;

Figure 1- CQL Tutorial - Check the definition of keyspace by using system_schema.keyspaces in CQL

Now if we would like to Alter TechBrothersTutorials keyspace from Replication Strategy "NetworkTopologyStrategy" to "SimpleStrategy" ,replication factor=3  and DURABLE_WRITES = true, we can use below statement. 

CQLSH:techbrotherstutorials> ALTER keyspace techbrotherstutorials 

WITH REPLICATION = {'class': 'SimpleStrategy', 'replication_factor' : 3}
AND durable_writes = true;

Let's check the definition of TechBrothersTutorials keyspace after executing above script to verification changes are completed successfully.

CQLSH:techbrotherstutorials>SELECT * FROM   system_schema.keyspaces;