In Oracle, there are some predefined User Accounts that basically helps in performing some task as follows:
- SYS User in Oracle is a user that is used to perform administrative level tasks.
- SYS Users have all kinds of privileges i.e insertion, updating, deletion, etc. of the data. However, it is not a good practice to alter data as an SYS User.
- The password for SYS User is set at the time of installation.
- SYSTEM User is another user that is introduced whenever the database is created.
- It has all the privileges like SYS user, except the one for removing and backup the data.
- This User also performs administrative level tasks and follows the same password as it was at the time of installation.
- SYSMAN user in Oracle represents the EM Admin account.
- EM stands for the Enterprise Manager account in Oracle that is used to monitor and manage the Oracle database.
- Oracle Enterprise Manager uses DBSNMP to monitor instances in a Database.
- DBSNMP read all the passwords from SYS users and use them to access the Database.