Can a trigger catch updates done by a select for update + lob.write()? It's maybe a stupid question, but I didn't find an explicit answer...

I want to catch any update on my oracle db, so I want to use triggers, but the triggers not been activated when using SELECT FOR UPDATE, then lob.write(...) and COMMIT. (I have tested it with c++ using occi) 

Is there any way to catch it in an update (or any other) trigger?

I find it hard to believe that there is command that can't be monitored by any trigger...

If it's matter I'm using version 11g.

Thanks!

EDIT

Trigger for example: 

CREATE OR REPLACE TRIGGER TR1
BEFORE DELETE OR INSERT OR UPDATE ON TEST_CLOB 
FOR EACH ROW
BEGIN
IF DELETING THEN
  WRITE_LOG('LOG_DIR','deleting:'||:old.filename);
  goto endproc;
END IF;
IF INSERTING THEN
  WRITE_LOG('LOG_DIR','inserting:'||:new.filename);
  goto endproc;
END IF;
IF UPDATING THEN
  WRITE_LOG('LOG_DIR','updating:'||:old.filename||'-'||:new.filename);
  goto endproc;
END IF;
WRITE_LOG('LOG_DIR','other:'||:old.filename||'-'||:new.filename);
&lt;&lt;endproc&gt;&gt;
NULL;
END;


Now in my log I see the inserting and deleting, but I never see any update.
Copied comment : 

You can't do that , at least up to 12c : "Using OCI functions or the DBMS_LOB package to update LOB values or LOB attributes of object columns does not fire triggers defined on the table that contains the columns or attributes." (docs.oracle.com/database/121/ADDCI/lobs.htm#ADDCI4383 )