Database users can change data in the database using SQL statements. To execute SQL statements, they either log on to the database via interfaces or using query tools such as Database Studio or SQLCLI. Note that database users cannot log on to Database Manager CLI or perform administration tasks in Database Studio.
Every database user belongs to a database user class (user mode DBA, RESOURCE, STANDARD). These database user classes have different authorization levels for the database. The database system administrator is a special database user of database user class SYSDBA (administrator).
The work processes of an SAP system always connect to the database as database users SAP<SAPSID>, SAP<SAPSID>DDB (Java EE systems) or SAPR3 (older systems), where <SAPSID> is the SAP system ID. You can assign special roles to database users in the SAP system ( Database Administration in CCMS, Prerequisites).
Database Administration in CCMS, User Data
Database Studio, Managing Users: Overview
SQL Reference Manual, Authorization
SQL Tutorial, Database Users and Their Privileges
SAP note 1542818