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;