==把表改成只读。
SQL> alter table trans read only;

Table altered.

SQL> select table_name,read_only from user_tables;

TABLE_NAME READ_ONLY
------------------------------ ----------
SALGRADE NO
BONUS NO
EMP NO
DEPT NO
TRANS YES

SQL> delete from trans where trans_id=102;
delete from trans where trans_id=102
*
ERROR at line 1:
ORA-12081: update operation not allowed on table "SCOTT"."TRANS"

SQL> update trans set cust_name='CUST_102' where trans_id=102;
update trans set cust_name='CUST_102' where trans_id=102
*
ERROR at line 1:
ORA-12081: update operation not allowed on table "SCOTT"."TRANS"

==把表改回可读写。
SQL> alter table trans read write;

Table altered.

SQL> update trans set cust_name='CUST_102' where trans_id=102;

1 row updated.

SQL> delete from trans where trans_id=102;

1 row deleted.

SQL> commit;

Commit complete.

SQL> select * from trans;

TRANS_ID CUST_NAME TRANS_DT TRANS_AMT STORE_ID ODD_
---------- -------------------- --------- ---------- ---------- ----
101 NLVULXSEUEGDDYEMJCSQ 06-JAN-08 28429555.7 23 ODD
110 cust_110 10-NOV-08 3543.12 23 ODD

这种小功能，早N个版本前就该出来了。