Stream triggers manipulation interfaces v5.6

You can create stream triggers only on tables with REPLICA IDENTITY FULL or tables without any columns to which TOAST applies.

bdr.create_conflict_trigger

This function creates a new conflict trigger.

Synopsis

bdr.create_conflict_trigger(trigger_name text,
                            events text[],
                            relation regclass,
                            function regprocedure,
                            args text[] DEFAULT '{}')

Parameters

  • trigger_name Name of the new trigger.
  • events Array of events on which to fire this trigger. Valid values are 'INSERT', 'UPDATE', and 'DELETE'.
  • relation Relation to fire this trigger for.
  • function The function to execute.
  • args Optional. Specifies the array of parameters the trigger function receives on execution (contents of TG_ARGV variable).

Notes

This function uses the same replication mechanism as DDL statements. This means that the replication is affected by the ddl filters configuration.

The function takes a global DML lock on the relation on which the trigger is being created.

This function is transactional. You can roll back the effects with the ROLLBACK of the transaction. The changes are visible to the current transaction.

Similar to normal PostgreSQL triggers, the bdr.create_conflict_trigger function requires TRIGGER privilege on the relation and EXECUTE privilege on the function. This applies with a bdr.backwards_compatibility of 30619 or above. Additional security rules apply in PGD to all triggers including conflict triggers. See Security and roles.

bdr.create_transform_trigger

This function creates a transform trigger.

Synopsis

bdr.create_transform_trigger(trigger_name text,
                             events text[],
                             relation regclass,
                             function regprocedure,
                             args text[] DEFAULT '{}')

Parameters

  • trigger_name Name of the new trigger.
  • events Array of events on which to fire this trigger. Valid values are 'INSERT', 'UPDATE', and 'DELETE'.
  • relation Relation to fire this trigger for.
  • function The function to execute.
  • args Optional. Specify array of parameters the trigger function receives on execution (contents of TG_ARGV variable).

Notes

This function uses the same replication mechanism as DDL statements. This means that the replication is affected by the ddl filters configuration.

The function takes a global DML lock on the relation on which the trigger is being created.

This function is transactional. You can roll back the effects with the ROLLBACK of the transaction. The changes are visible to the current transaction.

Similarly to normal PostgreSQL triggers, the bdr.create_transform_trigger function requires the TRIGGER privilege on the relation and EXECUTE privilege on the function. Additional security rules apply in PGD to all triggers including transform triggers. See Security and roles.

bdr.drop_trigger

This function removes an existing stream trigger (both conflict and transform).

Synopsis

bdr.drop_trigger(trigger_name text,
                 relation regclass,
                 ifexists boolean DEFAULT false)

Parameters

  • trigger_name Name of an existing trigger.
  • relation The relation the trigger is defined for.
  • ifexists When set to true, this function ignores missing triggers.

Notes

This function uses the same replication mechanism as DDL statements. This means that the replication is affected by the ddl filters configuration.

The function takes a global DML lock on the relation on which the trigger is being created.

This function is transactional. You can roll back the effects with the ROLLBACK of the transaction. The changes are visible to the current transaction.

Only the owner of the relation can execute the bdr.drop_trigger function.