Explain enabling and disabling triggers

ALTER TRIGGER trg DISABLE stops it firing without dropping it; ALTER TRIGGER trg ENABLE restores it. ALTER TABLE t DISABLE ALL TRIGGERS / ENABLE ALL TRIGGERS toggles every trigger on the table — common around a large data load or migration to avoid per-row overhead and unwanted side effects. A trigger that fails to compile is left in a disabled/invalid state. Check STATUS in USER_TRIGGERS. Remember that disabling audit triggers during a load leaves a gap you may need to backfill.

ALTER TRIGGER trg_emp_normalise DISABLE;

-- bulk load here, then:
ALTER TRIGGER trg_emp_normalise ENABLE;

-- or for the whole table:
ALTER TABLE employees DISABLE ALL TRIGGERS;
-- ...
ALTER TABLE employees ENABLE ALL TRIGGERS;

SELECT trigger_name, status FROM user_triggers WHERE table_name = 'EMPLOYEES';