Oracle Learning Notes (i)

After you install Oracle successfully, there are three users by default: SYS, System, Scott

Login command:
Sqlplus username/password @sid [as SYSDBA or Sysoper]


User:
SYS User: Super administrator, highest privilege, its role is DBA, default password is Change_on_install
System User: Administrator, the privilege is also very high, its role is dbaoper, the default password is the manager
Scott User: Normal user, default password is Tigger
SYS and SYSTEM
SYS has CREATE DATABASE permission, System no, other similar
In the daily management of Oracle, the system is sufficient.


Delete User
If the deleted user has already created the table, you need to take a parameter cascade;




Permissions
Divided into system permissions and object permissions.
System permissions: User-related permissions to the database, such as building a library, building users,
Object permissions: The user has access to data objects for other users, such as 25 Key object permissions.
The common system permissions are:
The common object permissions are:

Create session: Permissions to log on to the database


Assign the query permission of the Scott user's EMP to another user: Grant Select on EMP to Xiaoming;
The authorized user can be the owner of the table, or it can be an administrator, such as SYS, System.

Recover the query permissions of the Scott user's EMP from another user: Revoke select on EMP from Xiaoming;

Add, delete, change, and check permissions for the Scott user's EMP to other users: Grant all on the EMP to xiaoming;



Role
A role is a package of several permissions, with several permissions for each role.
Divided into auto-defined roles and pre-defined roles
Predefined roles: Connect
Common Predefined roles: Dba,connect,resource

Oracle Learning Notes (i)