LOBs and Triggers

You cannot write to a LOB (:old or :new value) in any kind of trigger.

In regular triggers, you can read the :old value but you cannot read the :new value. In INSTEAD OF triggers, you can read the :old and the :new values.

You cannot specify LOB type columns in an OF clause, because BFILE types can be updated without updating the underlying table on which the trigger is defined.

Using OCI functions or the DBMS_LOB package to update LOB values or LOB attributes of object columns will not fire triggers defined on the table containing the columns or the attributes.