Create a trigger after delete

Question

Hi,
I would a distributed database with two database. I have a orders tables on both the database. I would like to create a trigger for when deleting a record from one database would delete from the other database.
CREATE OR REPLACE TRIGGER orders_after_delete
AFTER DELETE ON orders
BEGIN
-- DELETE record into orders table in Database 1 (DB1)
END;
Thanks.

Answer 1

Your trigger is (after) STATEMENT level trigger.
What happens if you delete two (or more) rows using one DELETE statement:
ORA-01427: single-row subquery returns more than one row.
Use "WHERE o_id IN (SELECT...)"
instead of "WHERE o_id = (SELECT...)".
Another way is to use simple ROW level trigger:
CREATE OR REPLACE TRIGGER orders_after_delete
  AFTER DELETE ON orders
  FOR EACH ROW
BEGIN
  DELETE orders@DB1Link
   WHERE o_id = :OLD.o_id;
END;
/But, with row level trigger, one local DELETE statement launches more remote DELETE statements (one for each deleted row) .
This can cause performance and/or integrity problems (if table has self-referential integrity constraint, for example).
Regards,
Zlatko