About OLD and NEW Pseudorecords

When a row-level trigger fires, the PL/SQL run-time system creates and populates the two pseudorecords OLD and NEW. They are called pseudorecords because they have some, but not all, of the properties of records.

For the row that the trigger is processing:

• For an INSERT trigger, OLD contains no values, and NEW contains the new values.

• For an UPDATE trigger, OLD contains the old values, and NEW contains the new values.

• For a DELETE trigger, OLD contains the old values, and NEW contains no values.

To reference a pseudorecord, put a colon before its name—:OLD or :NEW—as in Example: Creating an INSTEAD OF Trigger.