> Lets pick a SAP system running on Oracle DB and you want to set it permanant as Read Only System To make the system in read only so that no one (none user) could make any changes into system, in this case changes made on abap side or program level will never updated into database. 1- Now stop SAP Application ( CI<Central instance>& DB <database instance>) 1.1 - Login to SAP NW OS box(suppose its Aix box) with sidadm user Use command stopsap à It will stop SAP (CI & DB both) 1.2 - Now Login to OS box with orasid and connect to database through SQL , then start database in mount phase & use sql command to open database in read only mode. sqlplus /as sysdba > startup mount > alter database open ready only ; > commit; 2. Now start SAP ...