Read only Table

A table can be set READ ONLY mode to restrict write operations.

• Enable table for READ-ONLY

SQL> alter table EMP read only; 
Table altered

• The READ_ONLY column of the user_tables confirms the change.

SQL> select table_name, read_only from user_tables where table_name='EMP';
 
TABLE_NAME                     READ_ONLY
------------------------------ ---------
EMP                            YES

• Making an attempt to do DML will fail.

SQL> update EMP set SAL=2000 where ENAME='SMITH';
 
update EMP set SAL=2000 where ENAME='SMITH'
 
ORA-12081: update operation not allowed on table "USER1"."EMP"

• Enable table for READ-WRITE

SQL> alter table EMP read write;
 
Table altered
 
SQL> select table_name, read_only from user_tables where table_name='EMP';
 
TABLE_NAME                     READ_ONLY
------------------------------ ---------
EMP                            NO