SAP Connection Mechanism
1. R/3 Work process loads all the DB Libraries.
2. DB_Connect to connect to database using client version
3. Users OPS$ User to connect to database and get the password of the SAPSR3 User.
It is a mechanism which is used by operating system users to connect to the database without any password.
All the work processes uses OPS$<SID>ADM to connect to the database without any password.
OPS$<SID>ADM is the user who owns the table SAPUSER and contains the SCHEMA OWNER SAPSR3 user and password.
Select table_name from dba_tables where owner = 'OPS$WILLSYS99NWDADM';
WP ------> SAPUSER (Table)
USERID | PWD
OPS$-User | XXX
Relogin with the above user and password
Disconnect from the DB and reconnect using SAPSR3 userid and password to get complete access.
SAPSR3 is the Schema/ DB Owner for SAP Database. As the processes are able to access the complete database related to schema owner, SAP restricts the access by using internal security.
You can view more tutorials about SAP BASIS