Triggers

Triggers are identified by a name defined by:

trigger_name ::=  identifier

CREATE TRIGGER

Creating a new trigger uses the CREATE TRIGGER statement:

create_trigger_statement ::=  CREATE TRIGGER [ IF NOT EXISTS ] trigger_name
                                  ON table_name
                                  USING string

For instance:

CREATE TRIGGER myTrigger ON myTable USING 'org.apache.cassandra.triggers.InvertedIndex';

The actual logic that makes up the trigger can be written in any Java (JVM) language and exists outside the database. You place the trigger code in a lib/triggers subdirectory of the Cassandra installation directory, it loads during cluster startup, and exists on every node that participates in a cluster. The trigger defined on a table fires before a requested DML statement occurs, which ensures the atomicity of the transaction.

DROP TRIGGER

Dropping a trigger uses the DROP TRIGGER statement:

drop_trigger_statement ::=  DROP TRIGGER [ IF EXISTS ] trigger_name ON table_name

For instance:

DROP TRIGGER myTrigger ON myTable;