CREATE TABLE ACTION_LOG (
USER_ID INTEGER,
USER_NAME VARCHAR2(30),
ACTION VARCHAR2(30),
ACTION_DATE DATE,
SES_USERNAME VARCHAR2(30),
SES_OSUSER VARCHAR2(30),
SES_MACHINE VARCHAR2(64),
SES_TERMINAL VARCHAR2(30),
SES_PROGRAM VARCHAR2(48),
SES_CLIENT_INFO VARCHAR2(64)
);



CREATE OR REPLACE TRIGGER TRG_ABC_USER_ACTION
BEFORE INSERT OR UPDATE OR DELETE
ON ABC_USER FOR EACH ROW
DECLARE
L_ACTION ACTION_LOG.ACTION%TYPE;
BEGIN
IF ( DELETING ) THEN L_ACTION := 'DELETE'; END IF;
INSERT INTO ACTION_LOG
SELECT :OLD.USER_ID, :OLD.USER_NAME, L_ACTION,
SYSDATE, S.USERNAME, S.OSUSER, S.MACHINE,
S.TERMINAL, S.PROGRAM, S.CLIENT_INFO
FROM V$SESSION S
WHERE S.AUDSID = USERENV('SESSIONID');
END;
/

SQL> CREATE TABLE abc_user ( user_id   VARCHAR2(30), user_name  VARCHAR2(30) );

Table created.

SQL> CREATE OR REPLACE TRIGGER TRG_ABC_USER_ACTION
  2  BEFORE INSERT OR UPDATE OR DELETE
  3  ON ABC_USER FOR EACH ROW
  4  
  5  DECLARE
  6  L_ACTION ACTION_LOG.ACTION%TYPE;
  7  BEGIN
  8  IF ( DELETING ) THEN L_ACTION := 'DELETE'; END IF;
  9  INSERT INTO ACTION_LOG
 10  SELECT :OLD.USER_ID, :OLD.USER_NAME, L_ACTION,
 11  SYSDATE, S.USERNAME, S.OSUSER, S.MACHINE,
 12  S.TERMINAL, S.PROGRAM, S.CLIENT_INFO
 13  FROM V$SESSION S
 14  WHERE S.AUDSID = USERENV('SESSIONID');
 15  END;
 16  /

Warning: Trigger created with compilation errors.

SQL> SHO ERR
Errors for TRIGGER TRG_ABC_USER_ACTION:

LINE/COL ERROR
-------- -----------------------------------------------------------------
5/1      PL/SQL: SQL Statement ignored
9/6      PL/SQL: ORA-00942: table or view does not exist

SQL> grant SELECT ON V_$SESSION TO MCHADDER;

Grant succeeded.

SQL> CREATE OR REPLACE TRIGGER TRG_ABC_USER_ACTION
  2  BEFORE INSERT OR UPDATE OR DELETE
  3  ON ABC_USER FOR EACH ROW
  4  
  5  DECLARE
  6  L_ACTION ACTION_LOG.ACTION%TYPE;
  7  BEGIN
  8  IF ( DELETING ) THEN L_ACTION := 'DELETE'; END IF;
  9  INSERT INTO ACTION_LOG
 10  SELECT :OLD.USER_ID, :OLD.USER_NAME, L_ACTION,
 11  SYSDATE, S.USERNAME, S.OSUSER, S.MACHINE,
 12  S.TERMINAL, S.PROGRAM, S.CLIENT_INFO
 13  FROM V$SESSION S
 14  WHERE S.AUDSID = USERENV('SESSIONID');
 15  END;
 16  /

Trigger created.

SQL> CREATE TABLE ACTION_LOG (
2 USER_ID INTEGER,
3 USER_NAME VARCHAR2(100),
4 ACTION VARCHAR2(100),
5 ACTION_DATE DATE,
6 SES_USERNAME VARCHAR2(100),
7 SES_OSUSER VARCHAR2(100),
8 SES_MACHINE VARCHAR2(100),
9 SES_TERMINAL VARCHAR2(100),
10 SES_PROGRAM VARCHAR2(100),
11 SES_CLIENT_INFO VARCHAR2(100)
12 );

Table created.

SQL> CREATE OR REPLACE TRIGGER TRG_ABC_USER_ACTION
2 BEFORE INSERT OR UPDATE OR DELETE
3 ON counter2005 FOR EACH ROW
4 
4 DECLARE
5 L_ACTION ACTION_LOG.ACTION%TYPE;
6 BEGIN
7 IF ( DELETING ) THEN L_ACTION := 'DELETE'; END IF;
8 INSERT INTO ACTION_LOG
9 SELECT :OLD.USER_ID, :OLD.USER_NAME, L_ACTION,
10 SYSDATE, S.USERNAME, S.OSUSER, S.MACHINE,
11 S.TERMINAL, S.PROGRAM, S.CLIENT_INFO
12 FROM V$SESSION S
13 WHERE S.AUDSID = USERENV('SESSIONID');
14 END;
15 /

Warning: Trigger created with compilation errors.

SQL> sho err
buffer overflow. Use SET command to reduce ARRAYSIZE or increase MAXDATA.
No errors.
SQL> remark ----> The current user have select access on V$SESSION

CREATE OR REPLACE TRIGGER DEL_TEST
BEFORE DELETE ON counter2005
 BEGIN
 RAISE_APPLICATION_ERROR(-20500,'cAN nOT dELETE.');
 END;

ERROR at line 1:
ORA-20500: cAN nOT dELETE.
ORA-06512: at "SHIFA.DEL_TEST", line 2
ORA-04088: error during execution of trigger 'SHIFA.DEL_TEST'

CREATE OR REPLACE TRIGGER DEL_TEST
BEFORE DELETE ON counter2005
 BEGIN
 RAISE_APPLICATION_ERROR(-20500,'cAN nOT dELETE.');
 END;

ERROR at line 1:
ORA-20500: cAN nOT dELETE.
ORA-06512: at "SHIFA.DEL_TEST", line 2
ORA-04088: error during execution of trigger 'SHIFA.DEL_TEST'