oracle different users

Oracle is a relational database management system that can manage and operate the database through different users. Different users have different permissions and roles, allowing them to control the security and flexibility of the database. This article will introduce the classification, permissions and applications of different users in Oracle.

1. User classification

Users in Oracle can be divided into two categories: system users and ordinary users.

1. System user

The system user is created by default and is used to manage the database. System users include SYS and SYSTEM. The former has data dictionary and system management permissions, while the latter has system management, database creation, backup and recovery permissions. These two types of users can only operate under SYSDBA authority.

2. Ordinary users

Ordinary users are created by administrators and are used for database applications. Ordinary users are divided into two types: connection users and owner users.

①The connection user is a user who connects to the database through a user name and password. He can only operate on the objects he owns. Since the connecting user only has basic operation permissions, other users and objects will not be affected. The usage scenarios are relatively wide, such as users when the application connects to the database.

②The owner user is the user who created the database object by the administrator. He has ownership of the object and can perform all operations on the object. Owner users can create tables, views, indexes, stored procedures, triggers, sequences, and other objects. Since the owner user has higher permissions, the administrator needs to strictly authorize and manage it.

2. User permissions

User permissions in Oracle can be divided into system permissions and object permissions.

1. System permissions

System permissions refer to the system-level operation permissions that can be performed on the entire database, such as defining users, creating tables, backing up and restoring, modifying the database, etc. System permissions can be granted to users through system privilege roles, including SELECT ANY TABLE, CREATE TABLE, DROP ANY TABLE, SYSTEM, DBA, etc.

2. Object permissions

Object permissions refer to the permissions that can operate on specific objects, including read and write operations, modification, deletion, etc. of objects such as tables, views, and sequences. Object permissions can only be granted by the object owner user.

3. User applications

User applications in Oracle can be divided into two categories: basic operations and advanced operations.

1. Basic operations

Basic operations mainly use SQL statements to perform simple add, delete, modify, and query operations, including INSERT, SELECT, UPDATE, and DELETE. These operations are mainly performed on table objects and are performed by connecting users. For example, use SELECT to query the table, and use INSERT to insert into the table.

2. Advanced operations

Advanced operations are mainly based on objects and PL/SQL language, including stored procedures, triggers, sequences, etc. These operations are mainly performed for the owner user and require the owner user to have higher permissions. For example, triggers are used to implement data integrity constraints, and stored procedures are used for data processing and business logic processing.

Conclusion

By introducing the classification, permissions and applications of different Oracle users, we can find that Oracle's user management provides a balance between flexibility and security. Administrators can create appropriate users, roles and permissions to achieve safe management and efficient application of the database. Therefore, when performing Oracle database applications, proper user management is required to achieve high-quality data processing and reasonable data security control.

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