Triggers

Triggers are identified with 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_nameON table_name

For instance:

DROP TRIGGER myTrigger ON myTable;